Mitt Romney’s support is holding steady, but conservative and Tea Party voters are fueling Newt Gingrich’s surge in New Hampshire, according to today’s Magellan Strategies poll:

If the election were held today, Romney would earn 29 percent of the vote and Gingrich would earn 27 percent. Texas Congressman Ron Paul continues to show resolve by earning 16 percent. Herman Cain gets 10 percent. No other candidate is in double digits. … 

A close look at the data shows Gingrich is actually leading Romney among certain important subgroups of the electorate. Among self-identified conservative voters, Gingrich beats Romney 34 percent-27 percent. Among self-identified Tea Party voters, he leads Romney 38 percent-21 percent.

This is a major jump from last month’s Magellan poll, which found Gingrich with just 6 percent support. The polling firm takes a crack at what may be driving this wave of enthusiasm:

When asked why people felt Gingrich was moving up in the polls, 44 percent of respondents cited his depth of knowledge on the issues. Ten percent referred to his strong debate performances while another 6 percent said they liked that he was challenging the media in those debates. Ten percent referenced his past experience as Speaker of the House.

Gingrich’s rise can’t be dismissed, especially so close to the New Hampshire primary. But it’s worth remembering that Herman Cain’s poll numbers went through a similar surge in the state last month, which now looks like it was transitory. In the August Magellan poll, Cain clocked in at just 3 percent; in October, he rose to 20 percent; and in today’s poll, Cain dropped back down to 10 percent.