The 2016 Democratic presidential race seems to be tightening in the final weeks leading up to the Feb. 1 Iowa caucuses and the Feb. 9 New Hampshire primary. According to recent polls, Senator from Vermont Bernie Sanders, widely seen as an underdog in the race, appears to be surging in early-state support and threatening to upset frontrunner and former Sec. of State Hillary Clinton.

A Wall Street Journal/NBC News/Marist poll taken Jan. 2 through Jan. 7 found Clinton clinging to a 48 percent to 45 percent lead over Sanders in Iowa, which lies within the survey’s margin of error. The New Hampshire version of the survey found Sanders leading with 50 percent support to Clinton’s 46 percent, also within the margin of error.

The Hill notes that a Monmouth University poll released Tuesday found Sanders beating Clinton 53 percent to 39 percent in New Hampshire. Last November, Clinton led Sanders in Monmouth University’s New Hampshire polling by 3 points, demonstrating that Sanders has gained significant ground in the Granite State.

A RealClearPolitics average of New Hampshire polls dated Jan. 2 through Jan. 10 finds Sanders leading by 6.2 percent, one of his strongest leads so far in the race. RealClearPolitics also found that Sanders has battled back from what was at one time a significant lead by Clinton in Iowa, as the company’s polling average over the same period of time found Clinton is now only up by a negligible 0.2 percent.

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Polling experts say that telephone polls are not as accurate as they once were back before the rise of mobile technology, particularly due to the theory that such methodologies might underestimate millennial support. However, given Sanders’ strong level of support among millennials, for his candidacy to be registering a dead heat against Clinton in traditional early-state polling suggests the possibility that his insurgent campaign has transformed what was an uphill battle against an establishment favorite into a competitive head-to-head race, at least in the early states.

Clinton still maintains a strong lead in national polling. A RealClearPolitics average of national polls dated Dec. 17 through Jan. 8 found Clinton leading by 12.8 percent. However, a Jan. 4 through Jan. 8 nationwide poll taken by Investor’s Business Daily and TechnoMetrica Institute of Policy and Politics found Clinton leading by only 4 points.

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