Rick Santorum’s momentum on a national level continues in the new Quinnipiac poll conducted among 1124 Republican primary voters.  The news is not so good among the larger sample of 2,605 registered voters, where Mitt Romney scores within the margin of error against Barack Obama, but Santorum trails by 10:

Former Pennsylvania U.S. Sen. Rick Santorum leads the Republican presidential field with 35 percent, followed by former Massachusetts Gov. Mitt Romney with 26 percent among Republicans and independent voters leaning Republican nationwide, according to a Quinnipiac University national poll released today. In November matchups, President Barack Obama edges Santorum, while the race with Romney is too close to call,

Santorum leads Romney head-to-head 50 – 37 percent.

Newt Gingrich and Ron Paul score in double digits, but still fall far off the pace at 14% and 11%, respectively. Santorum’s strength comes from Tea Party supporters and evangelical Christians, but the surprising demo for Santorum is women. He beats Romney 34/28 among women, just as Gallup found yesterday.  If Santorum’s attention to traditional conservative values and comments on the HHS contraception mandate damage him among women, it’s certainly not true among those women voting in the Republican primaries, at least according to this poll.

In the general election?  There’s actually not that much difference between Santorum and Romney:

Although this is Quinnipiac University’s first national poll this year, all of the numerous surveys of key states this year, including Florida, Ohio and Virginia, show Romney doing better against Obama than Santorum.

In this national poll, the president benefits from his 46 – 41 percent lead over Romney and 49 – 39 percent margin over Santorum among independent voters.

Obama wins women head-to-head against Romney in this poll by eight points, 49/41. He also wins independents 46/41, but loses Catholics by a huge margin of 35/56 — a big contrast to his 54/45 win in that demo against John McCain in 2008. However, Santorum loses women only by one point more, 50/41, but does worse among independents, losing by twice as much at 49/39. The Catholic vote stays the same, but Santorum does better with seniors (52/40) against Obama than does Romney (48/41).

The sample seems to be a little off, however, although not exactly tilted. The weighted D/R/I is 30/28/33, but another 8% are “other.” In other polls, those would go into the independent column, which would make this 30/28/41, a little too tilted toward the independents.  (The 2010 midterms produced a 35/35/30 split, for comparison.)  The sample doesn’t account for the R/I mix in the Republican primary polling, so it’s impossible to know whether Republicans were oversampled for that purpose (which would tend to help Santorum) or undersampled (which would tend to help Romney).