Updated

While far more Republican primary voters view Rick Santorum as the true conservative, Mitt Romney has become the clear leader in the race for the GOP nomination, according to a just-released Fox News poll.

After Iowa and New Hampshire wins, Romney now garners the highest level of support from GOP primary voters nationally achieved by any candidate so far. And support for Santorum has nearly quadrupled in the last month, putting him firmly in the second tier with Newt Gingrich and Ron Paul.

Romney has the backing of 40 percent of Republican primary voters. He’s followed by Santorum at 15 percent, Gingrich at 14 percent and Paul at 13 percent. Rick Perry captures 6 percent and Jon Huntsman 5 percent.

Click here for full Fox News poll results.

Romney’s support is up 17 percentage points since last month’s Fox poll. Gingrich -- who led last month -- has dropped by 22 points.

Among voters who are part of the Tea Party movement, Romney (30 percent) leads Santorum (21 percent) and Gingrich (18 percent). White evangelical voters give the edge to Romney over Santorum -- 32 to 23 percent.

Twenty-nine percent of primary voters say Santorum is the candidate best described as a true conservative. That’s nearly twice as many as pick Romney (15 percent), Gingrich (14 percent) or Paul (13 percent).

Still, another trait is more important to GOP primary voters -- electability. Fully 80 percent say it is “very” important their nominee can beat Barack Obama, compared with 42 percent who give the same weight to being a true conservative.

And by a wide margin Romney is seen as the one with the best chance of beating Obama: 63 percent say he’s the candidate most likely to do it. That’s seven times as many as say Gingrich (9 percent).

The ability to win in November also tops other candidate considerations such as having a business background (56 percent “very” important), and agreeing with the nominee on major issues (47 percent “very” important).

Republican primary voters have mixed views over which kind of candidate would be more likely to beat Obama: 49 percent think a more moderate Republican who will appeal to independents, while 43 percent think a more conservative Republican who will provide the sharpest contrast with Obama.

No other candidate comes close to matching the former Massachusetts governor when primary voters are asked who is most qualified to manage the economy. Forty-four percent say Romney, while 17 percent say Gingrich. Another 10 percent say Paul and 8 percent say Santorum.

Former House speaker Gingrich receives his highest score when asked which candidate would do the best job working with Congress. Yet even here Romney has the edge -- 35 percent to 28 percent.

Meanwhile, three times as many say Gingrich (27 percent) as say Romney (8 percent) would be a “bad choice” to represent the party.

And twice as many say Gingrich (29 percent) has run the nastiest campaign as say Romney (13 percent).

Romney (27 percent) and Santorum (20 percent) are seen as the candidates running the most positive campaigns.

Finally, likeability plays a role in elections, and here again Romney has the advantage. A 69-percent majority of GOP primary voters have a favorable opinion of him. The next closest is Santorum at 50 percent favorable.

The Fox News poll is based on landline and cell phone interviews with 906 randomly-chosen registered voters nationwide and was conducted under the joint direction of Anderson Robbins Research (D) and Shaw & Company Research (R) from January 12 to January 14. For the total sample, it has a margin of sampling error of plus or minus 3 percentage points. For the subgroup of 365 GOP primary voters it is plus or minus 5 percentage points.