Washington ? Rick Santorum is falling so far behind Mitt Romney in the race for Republican delegates that his best chance might be in states that voted weeks ago.

The chief rival to the front-running Romney, Santorum is trying to improve his lot in places like Iowa and Washington, where local caucuses were just the first step in determining delegates to the Republican National Convention. In those states and a few others, supporters are now preparing for county, congressional district and state conventions, where the campaigns hope to keep their delegates — and possibly poach some from other candidates.

Santorum’s delegate count could use a boost. He trails Romney by 300 and would need to win 74 percent of the delegates in the remaining primaries to clinch the nomination before the national convention in August. So far, Santorum is winning just 27 percent, according to the tally by The Associated Press.

But the former Pennsylvania senator’s campaign predicts that he will significantly increase his delegate haul in caucus states, primarily at the expense of Romney.

“The Romney campaign likes to talk about how they have this superior organization in these caucus states and therefore they are going to perform well,” said John Yob, Santorum’s national delegate director. “If you believe the Romney campaign’s spin that they have this superior organization, but yet they’re losing these contests, it must mean they have a deficient candidate who is unable to appeal to the base of the party.”

That assessment is simply laughable, Romney’s campaign says. And his backers question whether Santorum has a sufficient organization to compete in upcoming primaries while also trying to rally supporters in states that held caucuses weeks or months ago.

This weekend, for example, Louisiana holds its GOP primary on Saturday, the same day county conventions kick off in Washington state.

Romney leads the race for delegates with 563, including endorsements from Republican National Committee members who automatically attend the convention and can support any candidate they choose. Santorum has 263 delegates, former House Speaker Newt Gingrich has 135 and Texas Rep. Ron Paul has 50.

It takes 1,144 delegates to win the Republican nomination to take on President Barack Obama in the fall.