New Hampshire is often noted for its moderate politics and its status as a prominent swing state. Voters predominantly selected Republicans for national office during the 19th and 20th centuries until 1992. Since then, the state has been considered as a swing state, and the Cook Political Report now classifies New Hampshire as "Even" after the 2016 election, reflecting that neither party has an advantage. Since 2006, control of the state legislature and New Hampshire's congressional seats have switched back and forth between Republicans and Democrats in a series of wave elections.
Due to its large State House, the annual town meetings in most communities, and the prominence of the New Hampshire Primary every four years, New Hampshire has been noted for its high level of political participation and retail politics.[ clarification needed] Some have called politics the "state sport." 
Historically, New Hampshire was a staunchly conservative state and regularly voted Republican, with only Hillsborough County leaning Democratic before the 1970s. Some sources trace the founding of the Republican Party to the town of Exeter in 1853. Prior to 1992, New Hampshire had only strayed from the Republican Party for three presidential candidates— Woodrow Wilson, Franklin D. Roosevelt and Lyndon B. Johnson. The state voted for Presidents Richard Nixon and Ronald Reagan twice by overwhelming majorities.
Beginning in 1992, New Hampshire became a swing state in both national and local elections. The state supported Democrats Bill Clinton in 1992 and 1996, John Kerry in 2004, and Barack Obama in 2008 and 2012. Among the states that George W. Bush won in the 2000 election, it was the only one to go Democratic in the 2004 election. The state elected two Democrats to the Governorship during this period.
The voters selected Democrats in New Hampshire as they did nationally in 2006 and 2008. In 2006, Democrats won both congressional seats (electing Carol Shea-Porter in the 1st district and Paul Hodes in the 2nd district), re-elected Governor John Lynch, and gained a majority on the Executive Council and in both houses of the legislature for the first time since 1911. Democrats had not held both the legislature and the governorship since 1874.  Neither U.S. Senate seat was up for a vote in 2006. In 2008, Democrats retained their majorities, governorship, and congressional seats; and former governor Jeanne Shaheen defeated incumbent Republican John E. Sununu for the U.S. Senate in a rematch of the 2002 contest. At the end of the 2008 election cycle, voters registered Democratic outnumbered those registered Republican.
A 2006 University of New Hampshire survey found that New Hampshire residents who had moved to the state from Massachusetts were mostly Republican. The influx of new Republican voters from Massachusetts has resulted in Republican strongholds in the Boston exurban border towns of Hillsborough and Rockingham counties, while other areas have become increasingly Democratic. The study indicated that immigrants from states other than Massachusetts tended to lean Democratic. 
In the 2010 midterm elections, New Hampshire voted out both of its Democratic members in the House of Representatives in favor of Republicans. Republicans also won control of both chambers of the State House by veto-proof majorities, while Governor John Lynch, a Democrat, won a fourth term, unprecedented in modern times.
Two years later, in the 2012 elections, New Hampshire voted out both of its Republican members in the House of Representatives in favor of Democrats. At the same time, voters returned Democrats to the majority in the State House of Representatives, while Republicans held on to a narrow 13-11 majority in the state Senate, despite losing the popular vote. Democrat Maggie Hassan won a surprisingly large 12% margin of victory, with 54.6% of the vote in the gubernatorial election, becoming the first Democrat to succeed another Democrat as Governor of New Hampshire since 1854.
In 2016 elections Republicans gained control of the governor’s office and both chambers of the state legislature, giving full power at the state level to Republicans.  However, the state narrowly went to Democrat Hillary Clinton over Republican Donald Trump in that year's presidential election, while former Democratic governor Maggie Hassan defeated incumbent Republican Kelly Ayotte to join Senator Jeanne Shaheen and Representatives Carol Shea-Porter and Ann McLane Kuster to make the entire United States congressional delegations from New Hampshire represented by the Democratic party.
Due to New Hampshire's large legislature and the state's history of volunteerism, women have held more political positions in the state than in many others. Since 1975, women have made up at least one-quarter of the state legislature. 
The 2008 elections resulted in women holding the majority of seats (13 of the 24) in the New Hampshire Senate, a first for any legislative body in the United States. 
Following the 2012 elections, New Hampshire had the first all-female congressional delegation in the country, when Carol Shea-Porter and Ann McLane Kuster were elected to the House of Representatives, joining Senators Jeanne Shaheen and Kelly Ayotte, who had been elected in 2008 and 2010, respectively.  The 2012 election also saw New Hampshire elect its second female governor, Maggie Hassan.
Following the 2016 elections, New Hampshire had the first all-female, all-Democratic delegation in the country, when Maggie Hassan defeated incumbent Republican senator Kelly Ayotte in the New Hampshire senate race. Hassan serves alongside Democratic senator Jeanne Shaheen. In the US House, Carol Shea-Porter, a Democrat, defeated incumbent Representative Frank Guinta to represent the 1st Congressional District in New Hampshire again and serving alongside Representative Ann McLane Kuster, a Democrat, who won re-election to represent the 2nd Congressional District. 
Same-sex marriage became legal in New Hampshire on January 1, 2010, replacing civil unions, which had become legal on January 1, 2008. In doing so, New Hampshire became the first state to recognize same-sex marriage entirely through the legislative process.
After winning veto-proof majorities in both houses of the state legislature in 2010, the Republican leadership in the House attempted to repeal New Hampshire's same-sex marriage law. On March 21, 2012, however, the House defeated the repeal bill on a vote of 211 to 116. 
New Hampshire has also been noted for its libertarian tendencies, with its history of social libertarianism and fiscal restraint. New Hampshire perennially provides popular resistance to proposed seat-belt and motorcycle-helmet laws. Automobile insurance is optional under normal circumstances. 
The state motto of " Live Free or Die" is another political touchstone. In 2006, when welcome signs at the border began to display the marketing slogan, "You're Going to Love It Here," a firestorm erupted and Governor John Lynch acceded to a privately financed effort to erect new signs bearing the state motto. In 1997, a comparable firestorm had greeted a new issue of car license plates on which the motto was printed rather than embossed; the design was promptly changed to increase the size of the motto. (However, the U.S. Supreme Court had ruled in 1977 that those who object to the motto may tape over or cover up the words, either partially or completely. )
When Senator Judd Gregg included an earmark in the REAL ID Act to compensate New Hampshire for being the first state to implement the Act in 2007, the state legislature enacted a law  calling the Act "contrary and repugnant to" the state and federal Bill of Rights and prohibiting the state executive branch from implementing it. 
New Hampshire's libertarian reputation led the Free State Project to select it by vote for a mass in-migration.  Roughly 20 Free Staters, many of whom moved to New Hampshire specifically to participate in the Free State Project, have been elected state representatives, including roughly 10 who are currently serving, but none have been elected to higher offices. Many of those who have run have not made their affiliation with the Free State Project a prominent feature of their campaigns.  The Free State Project has met with opposition not only from Democrats, but also from many within the Republican Party, the party in which most Free State-affiliated candidates have run. 
Some Free Staters have conducted acts of civil disobedience to demonstrate their opposition to what they call "victimless crimes." Free Keene, a group of Free Staters in that city, has attracted particular attention to the high number of acts of civil disobedience, which have often been considered confrontational, and their effect on Keene's image and economy.  In recent years, a group of Free Keene members, calling themselves "Robin Hooders" have fed expired parking meters and videotaped their encounters with the parking enforcement officers, suggesting that the officers should refrain from writing tickets and get a different job. The close encounters with the "Robin Hooders" resulted in one officer resigning his position and a lawsuit filed by the City of Keene citing harassment of their employees.  In December 2013, the judge overseeing the case dismissed the city's arguments against the "Robin Hooders" on first amendment grounds, citing the public sidewalks' role as a traditional public forum. 
During the Pumpkin Festival Riots of 2014 the Free Keene group claimed the police should have done more to stop the crimes being committed. 
Taxation is a perennial electoral issue in New Hampshire, where there is strong opposition to "broad-based" taxes. Their absence is not absolute; there is a 9% tax on meals and rentals,  and a 5% income tax on dividends and interest;  moreover, the state's 8.5% Business Enterprise Tax  is essentially an income tax on sole proprietors. However, candidates for legislature and Governor are routinely asked to take " The Pledge" against broad-based taxes.
The property tax is the source of nearly all municipal revenue. It is "broad-based" (affecting even renters, indirectly) but does not attract the same controversy because municipal expenditures are voted locally, typically by Town Meeting, in which every voter can participate.
In 2002, in response to court-ordered statewide equalization of education funding (see the Claremont Decision), New Hampshire instituted a statewide property tax. The tax is lower than the amount already assessed by municipalities, it is collected by municipalities, and is essentially returned to them, though legislative adjustments create "donor towns" and "recipient towns." Each new legislature has considered changes to the distribution formula.
Taxes that are not "broad-based" (that is, that residents could avoid paying) have not aroused comparable controversy. For example, the meals and rentals tax disproportionately impacts tourists and visitors, who do not vote. Recent legislatures have covered increased spending with increases in sin taxes, tolls, and filing fees. Some feel it would be simpler and fairer to enact a broad-based tax; in 2008, various Town Meetings considered citizen petitions against "The Pledge." In particular, the property tax is seen as unfairly impacting the poor and especially retirees. Advocates of a state broad-based tax say it would permit higher state payments to municipalities, enabling them to lower property taxes. The opposing argument is that a new state tax would not change this alleviate local taxes, but would eventually lead to more state spending.
New Hampshire's lower tax burden has also induced contiguous Amesbury and Salisbury, Massachusetts, and not-nearly-contiguous Killington, Vermont in 2004 and 2005, to petition to become part of New Hampshire.  This reflected local discontent with restrictions on liberty or profitability, rather than any expectation that their own states plus the U.S. Congress would grant the necessary permission.
- Free State Project
- Government of New Hampshire
- Libertarian Party of New Hampshire
- New Hampshire Democratic Party
- New Hampshire Liberty Alliance
- New Hampshire primary
- New Hampshire Republican State Committee
- Political party strength in New Hampshire
- Town meeting
- Kocher, Fred (2006-12-22). "Storm of change sweeps through N.H. Legislature". Mass High Tech: The Journal of New England Technology. Retrieved 2008-04-28.
- New Hampshire Union-Leader: "Hey, don't blame Massachusetts." November 12, 2008.
- Senate President Sylvia Larsen, quoted in "Women make up majority in state Senate," the Manchester Union-Leader, November 6, 2008.
- Geiger, Kim (March 21, 2012). "New Hampshire House rejects repeal of gay marriage law". Los Angeles Times. Retrieved August 13, 2013.
- Schweitzer, Sarah (November 6, 2012). "Obama wins N.H.; Hassan elected governor". Boston Globe. Retrieved August 15, 2013.
- Love, Norma (November 7, 2012). "NH House flips back into Democratic control". Boston Globe. Retrieved August 15, 2013.
- New Hampshire Motor Vehicle Insurance Questions & Answers
- Wooley v. Maynard, 430 U.S. 705 (1977). The Slate blog discusses the issues at Poetic Licenses
- RSA 243:1, Prohibition against Participation in a National Identification System.
- A nearly identical bill, SCR-8 of 2006, did not pass the legislature (tabled 14-9 in the Senate).
- "Free State Project: State Vote Results"
- "Is Keene Turning Into a Battleground for Activists, Police?". WMUR-TV News 9. February 21, 2011. Archived from the original on December 23, 2011.
- "'Robin Hooders' face lawsuit for plugging parking meters". WHDH-TV News 7. May 14, 2013. Archived from the original on October 23, 2013.
- Judge Cites First Amendment in Dismissing Keene Case
- Schweitzer, Sarah (November 6, 2012). "Obama wins N.H.; Hassan elected governor". Boston Globe. Retrieved August 15, 2013.
- RSA 78-A
- RSA 77. Until 1995, the income tax exempted dividends and interest from institutions within the state (and, reciprocally, from institutions in Vermont). This was found to violate the Privileges and Immunities Clause of the U.S. Constitution.
- "CNN.com - Killington residents vote to secede from Vermont - Mar. 4, 2004". Archived from the original on April 7, 2008.