Sen. Marco Rubio, R-Fla., center, and others Senators, participate in a news conference on immigration, Thursday, April 18, 2013, on Capitol Hill in Washington. From left are, Sen. Charles Schumer, D-N.Y., Sen. John McCain, R-Ariz., Sen. Jeff Flake, R-Ariz., Rubio, Senate Majority Whip Richard Durbin of Ill., and Sen. Robert Menendez, D-N.J. (AP Photo/Charles Dharapak) Sen. Marco Rubio (R-Fla.), center, and other  senators on April 18  on Capitol Hill. (Charles Dharapak/AP)

Sen. Marco Rubio (R-Fla.) has lost significant ground with voters in the first-in-the-nation primary in New Hampshire in the months since he took a leading role on comprehensive immigration reform.

A new Granite State Poll conducted for WMUR-TV shows Rubio, who was tied with Sen. Rand Paul (R-Ky.) for the lead in an April poll by the same pollster at 15 percent, now garners the support of just 6 percent of New Hampshire GOP primary voters, placing fifth.

Rubio's favorable rating has also taken a hit. While in April he was viewed favorably by 59 percent and unfavorably by 8 percent, his favorable-unfavorable split is now 47-14.

The poll's new leader is New Jersey Gov. Chris Christie, at 21 percent. He is followed by Paul at 16 percent, former Florida governor Jeb Bush at 10 percent, Rep. Paul Ryan (Wis.) at 8 percent and Rubio at 6 percent.

Of those five, Rubio is the only one whose favorable rating has dropped in recent months. (Ryan's favorable rating has gone from 68 percent to 66 percent, but that's within the margin of error and is not statistically significant.)

On the Democratic side, the leader is — surprise, surprise — Hillary Clinton. She leads Vice President Biden by a huge margin, 62 to 8.

Massachusetts Gov. Deval Patrick is third at 5 percent, while New Jersey Senate candidate Cory Booker is at 2 percent and New York Gov. Andrew Cuomo is at 1 percent. No Democrat outside the Northeast and the Mid-Atlantic states registers significant support.

The 2016 New Hampshire primary, of course, is still two and a half years away, and plenty will happen during that period to change the race — not least the fact that none of these candidates are officially in the race yet.

But the poll is one of the first to suggest that Rubio may be paying a political price for putting his political brand on the line in the current immigration debate.

Polls suggest there is considerable resistance among conservative voters to a path to citizenship for illegal immigrants, and House Republicans have balked both at voting on the Senate-passed bill and at the idea of crafting their own comprehensive immigration bill.