Set to host its Democratic primary on Feb. 11, 2020, New Hampshire has earned a reputation not only as a key swing state in general elections, but as an early battleground state in both major parties' presidential primaries.

Only Iowa holds its election earlier, so if presidential candidates want to contend nationally, they must fare well in New Hampshire or risk fading into irrelevance. This time around, former Vice President Joe Biden holds a slight lead in the New Hampshire polls with the election nearly six months away. But it is the progressive wing of the Democratic field — Sen. Elizabeth Warren of Massachusetts and Sen. Bernie Sanders of Vermont — which has a major and oft-overlooked advantage in New Hampshire: geography.

Both Warren and Sanders represent states which neighbor New Hampshire. In fact, Warren's home in Cambridge is just about 40 miles from Nashua, NH, and Sanders lives just a 90 mile drive from the state line. This gives the candidates the advantage of being able to campaign in the state frequently when they are home. NBC Boston reports that so far, Warren has made 36 stops in state and Sanders has made 27, but Biden has only made 17. If the past is any precedent, this could work in their favor.

Typically, major candidates from states surrounding New Hampshire have fared well in its primaries. Last time around, Sanders defeated Hillary Clinton in New Hampshire and even got 4,493 write-in votes in the state’s general election.

Prior to that, former Massachusetts Governor Mitt Romney fared well on the Republican side, winning the state in 2012 and finishing second to the late Sen. John McCain in 2008. On the Democratic side in 2004, then-Massachusetts Sen. John Kerry and former Vermont Governor Howard Dean finished first and second respectively in New Hampshire.

Back in 1992, then-Massachusetts Sen. Paul Tsongas won the state, topping future President Bill Clinton and four years prior, then-Massachusetts Governor Michael Dukakis won the New Hampshire primary and later the Democratic nomination.

And in the 1960s, a pair of Massachusetts natives won New Hampshire in their respective party’s primaries. Henry Cabot Lodge Jr., a Massachusetts resident, defeated the far more conservative Barry Goldwater in the state Republican Primary as a write-in vote without campaigning. And John F. Kennedy, a Massachusetts senator at the time, prevailed in the New Hampshire Democratic Primary in 1960.

In addition to the ability of visiting the state more frequently, regional values factor into the advantage, as does candidates being familiar with local issues.

The best example of this would be Lodge Jr. winning New Hampshire in 1964 at a time where conservatives wanted to take over the Republican Party. Lodge Jr. didn't campaign or even want the nomination and yet, a write-in campaign started on his behalf beat those actually running for the nomination.

Granted, for Rep. Seth Moulton of Massachusetts, living in Lawrence, one town south of the Massachusetts-New Hampshire border, did not do much, as his campaign has already suspended. But home turf can’t hurt Sanders and Warren. According to RealClearPolitics, they are consistently polling second and third in NH respectively, within single digits of Biden. In the nearly six months leading up to the primary, they could surpass Biden as he continues making regular gaffes — like when he recently referred to Keene, New Hampshire as Vermont.

Nonetheless, if the Democrats veer too far to the Left and nominate one of their New England liberals, they still risk alienating moderate New Hampshire voters who might otherwise vote for Biden. One thing’s for sure: Geography will play a bigger role than you might expect.

Tom Joyce (@TomJoyceSports) is a freelance writer and a contributor to the Washington Examiner’s Beltway Confidential Blog.