Mitt Romney has consistently remained a front-runner all year long.  Herman Cain’s polling burst looks like it might be descending, while Newt Gingrich’s ascends.  Is there room for anyone else at the top?  Iowa caucus goers seem to think so, at least in one new poll for Bloomberg News:

Herman Cain, Ron Paul, Mitt Romney and Newt Gingrich are in a dead heat as the top choices for Iowans likely to attend the Jan. 3 Republican presidential caucuses.

A Bloomberg News poll shows Cain at 20 percent, Paul at 19 percent, Romney at 18 percent and Gingrich at 17 percent among the likely attendees with the caucuses that start the nominating contests seven weeks away.

Economic issues such as jobs, taxes and government spending are driving voter sentiment, rather than such social issues as abortion and gay marriage, the poll finds. Only about a quarter of likely caucus-goers say social or constitutional issues are more important to them, compared with 71 percent who say fiscal concerns.

The poll reflects the race’s fluidity, with 60 percent of respondents saying they still could be persuaded to back someone other than their top choice, and 10 percent undecided. Paul’s support is more solidified than his rivals, while Cain’s is softer. All of the major contenders have issue challenges to address.

Bloomberg makes sure to point out in its report that it used the same polling firm as the Des Moines Register, whose caucus polling is considered the gold standard for Iowa predictive surveys.  The sample size is more than adequate at 503 likely caucusgoers.  At an MOE of +/-4.4%, this basically shows Iowa at a dead heat among the four contenders.

Obviously, this is good news for Ron Paul, who hasn’t polled this well nationally.  Paul has always had a strong base of support in Iowa; he nearly won the Ames poll, coming within less than 200 votes in an event that Michele Bachmann had thought she owned.  Iowa rewards organization, and the Paul campaign is all about organization and getting people to participate in polls.  It’s also good news for Gingrich, who doesn’t have that kind of organizational strength, at least not yet.  This isn’t bad news for Cain, at least not explicitly, but it does show that some of the support he might otherwise be getting is going elsewhere now.

This is pretty good news for Mitt Romney, too, in a couple of ways.  First, no one expected him to compete hard in Iowa, but he’s been hanging on as a frontrunner here since Rick Perry’s polling collapse in October.  Second, if these numbers for Paul aren’t a polling fluke — so far this result is very much an outlier — it might push some Iowa Republicans into Romney’s camp as a safe choice rather than take a flier on Cain or Gingrich.

For those outside of the top four, this is very bad news, especially for Perry and Bachmann.  Neither one have a real path to victory without Iowa, and leapfrogging four different Republicans to win this state will be almost impossible.  If further polling bears this out, they may run out of reasons to stay in the race — and may start running out of money, too.