Six weeks ago, the WBUR poll of all likely Republican primary voters had Donald Trump leading with 27% and Chris Christie charging into second place with 12%. Marco Rubio and Ted Cruz stayed hot on Christie’s trail in double digits. John Kasich was an afterthought in sixth place.

In today’s WBUR poll, which focuses on independents alone, the leader remains the same — Trump, at 26% — but nearly everyone else has shuffled position. Kasich more than doubled his early December level of support to hit 15%, putting him in a tie with Cruz for runner-up. Christie and Rubio have both faded to single digits. But more importantly, a large percentage of the state’s independent voters — who can choose in which primary to vote — still haven’t made up their minds:

A new WBUR poll out Thursday (topline, crosstabs) finds that with less than three weeks before primary day, a large share New Hampshire’s undeclared voters have yet to make up their minds about who to vote for — or even which party to support.

New Hampshire’s undeclared voters — those who aren’t registered as Democrats or Republicans and can choose either ballot on Election Day — represent over 44 percent of the state’s voters, more than either political party. They are notoriously independent and play a crucial role in picking the winners.

“And a lot of them, about a third, still haven’t made up their mind,” said Steve Koczela, president of The MassINC Polling Group, which conducted our survey. “That to me is the thing that could still cause the biggest change.”

This could well be an outlier, and it doesn’t take into account voters registered in either party — only the independents. Rubio still mostly polls in double digits in recent surveys, although Christie has definitely fallen off the pace. The sample size is rather small for this close to the election at 436 likely voters — but the focus on only unaffiliated voters makes it a stronger poll than the sample size would indicate. The independent vote drives election results, and while this new WBUR poll design makes it difficult to compare to other surveys, the results are pretty fascinating nonetheless.

WBUR’s polling attempts to take into account the flux among ballot choices for independents by offering six models of indy turnout in both primaries. Trump and Kasich remain 1-2 in all six, but the margins shift significantly:

The more independents cross over, the weaker Trump and Cruz become and the stronger Kasich and Bush perform. Interestingly, none of the other candidates seem to see any impact from the percentage shifts of independents choosing to vote in the GOP primary. Who would have guessed that Rubio was doing worse among independents than Cruz? Hmmm. According to the soft commitment indicated by the survey, the 41/59 model may be closest to the reality among independents.(And remember, this poll doesn’t include registered Republicans.)

If nothing else, this may prove that debate performances don’t matter much in the early states. What has Kasich done in any recent debate to set himself up for this kind of boost? Not much, but in heavy-retail-politics states like New Hampshire, TV matters less than personal campaigning, especially for the independents polled in this survey. Kasich has been focusing his attention on the Granite State, but … so has Marco Rubio, Chris Christie, and Jeb Bush. This Kasich bump looks suspiciously similar to the Not-Romney bubbles from 2011-12 — the latest flirtation with the Trump Alternative. Maybe he’s peaking at just the right time, but Kasich had better hope that there isn’t a Second Look At Fiorina movement next week.

Over on the Democratic side, the WBUR poll shows a meltdown for Hillary Clinton among independents. WBUR hasn’t polled the New Hampshire Democratic primary since October, when they had Hillary Clinton leading 38/34 among all Democratic primary voters. Today’s poll of indies puts Sanders in the lead by 27 points, 60/33. Unlike the GOP side of the poll, the numbers for Democrats don’t show much change based on independent participation, either:

Only in the two heaviest indie-turnout models do the numbers change for Hillary … and in the wrong direction.

Right now, New Hampshire belongs to the outsider candidates. The big question, assuming WBUR’s polling accurately reflects the mood of the state, will be whether Trump and Sanders can manage a voter-turnout operation among independents well enough to take advantage of their standing, and whether Kasich’s surge is real and can be translated to votes. With a lead this large among indies, and a 12.6-point lead in the overall RCP average among all New Hampshire Democratic primary voters, Sanders’ GOTV expertise may not matter at all.