After his big primary victory in Louisiana on Saturday, Rick Santorum isn’t listening to the people in his party who say it’s time to start coalescing around Mitt Romney. Santorum says there would be nothing better for the Republican Party than a long nomination battle and a short general election.

Speaking with reporters over coffee on Capitol Hill Monday morning, Santorum said Republicans would be better off with a relatively brief general election campaign because it would negate the financial advantage he expects President Obama to have over the Republican nominee.

A short campaign is the “best thing that could happen,” he said. “If we only have a two-month campaign, their money advantage . . . won’t make as much difference. There’s only so much money you can spend in two months. . . . If we have a nominee next week, all of the money advantages they have now are going to be trained on destroying whoever the nominee is.”

The former Pennsylvania senator sounded ready to do whatever he could to make sure the nomination contest runs as long as possible. With about half the states having voted, he pointed to the fact that Romney has fewer than half of the 1,144 delegates needed to win the nomination. “Our feeling is we have just as good a chance of getting there as he does. It’s going to be hard for anybody to get there.”

He also argued that his deficit in the delegate race is less than some organizations have tallied. “Our math is actually based on reality of what’s going on in the states as opposed to this fuzzy idea that it’s going to be apportioned based upon what the votes are in the states.”

Santorum’s campaign advisers made a similar argument last week and on Monday the candidate promised that they would follow that with a detailed, written estimate of where they see the delegate battle with Romney.

Santorum acknowledged that he faces a difficult month in April and sounded pessimistic about being able to win next Tuesday’s primary in Wisconsin, which shapes up as the next showdown with Romney.

Santorum said he believes he will win Pennsylvania’s primary on April 24, but acknowledged that some of the other states that vote that day—among them New York, Rhode Island and Connecticut—will be far more difficult.

“Obviously Connecticut and Rhode Island are not necessarily in my sweet spot,” he said.

Santorum said he is looking forward to the month of May, when states like Texas, Arkansas, Kentucky, North Carolina, West Virginia, Oregon and Nebraska hold contests. “If you look at the May calendar, that’s a very, very nice calendar for us,” he said. “I think we can go out there and . . . come close to winning everything in May.”

As if to emphasize the disagreement with Romney over health care, Santorum spent Monday in Washington and even held a campaign event outside the Supreme Court as the justices were concluding the first of three days of oral arguments on the constitutionality of the national health-care overhaul. Romney was in California on a trip mostly devoted to fundraising.

Santorum’s campaign has used the days surrounding the high court’s oral arguments to step up its attacks on Romney, with daily e-mails highlighting the Massachusetts law and what campaign officials say was Romney’s advocacy for using his state as a model for national health care reform.

Santorum has said repeatedly that Romney would be an extremely poor choice as nominee because he would forfeit one of the biggest issues Republicans should have to run against Obama in the general election.

“It is the mega issue,” he said. “It is the biggest issue and it’s one as you’ve seen President Obama won’t talk about. He’s not running around defending this thing. It is his huge Achilles’ heel and I argue we’re putting up the one guy who can’t make the case.”

Santorum made a similar comment over the weekend, calling Romney “the worst Republican in the country to put up against Barack Obama.” Later he blew up at New York Times reporter Jeff Zeleny, who asked him to clarify the comment.

“Stop lying!” he said. “I said he was the worst Republican to run on the issue of Obamacare. And that’s what I was talking about!” He uttered an expletive to show his displeasure at what he said were distortions by the media about his positions.

Santorum’s campaign sent out a fundraising appeal early Monday morning based on that exchange. A campaign official said the e-mail had generated a big response.

Santorum said Monday that Romney has been hurt badly in the primaries because of the Massachusetts law. “I think that’s one of the reasons the jury’s still very much out,” he said.

He added that, were it not for the former governor’s huge financial advantages, the nomination contest would be far closer than it is today. He said Romney has benefited from spending the last four years courting the Republican establishment for money and support.

“He’s worked the establishment. I haven’t,” the former Pennsylvania senator said. “I don’t call these guys up on the Hill. I don’t call governors. . . . If you look at the fact that we’ve now won 11 states, it’s pretty remarkable given the resources we’ve had.”