Updated 3:20 p.m. ET
DAYTON, Ohio - Mitt Romney's campaign wasted no time on Saturday in making clear it regards Rick Santorum's organizational problems as an issue it can exploit in gaining ground on its bitter rival in Ohio as well as other critical "Super Tuesday" states.
The Romney campaign held a conference call with reporters to argue that the ex-Pennsylvania senator's failure to submit required paperwork - something that would deny him convention delegates even if he wins in certain areas -- shows his campaign is not up to the challenge of running for president.
But Santorum sought to minimize the political fallout from the issue. Speaking to reporters in Wilmington, Del., the former Pennsylvania senator said he's not concerned about how the situation might affect him.
"If that's the only thing that they find is a problem with my candidacy, we're in pretty good shape," he said.
He also said he's "very very proud of the work that we've done" and that he is optimistic he can emerge "in good shape with a lot of delegates."
When news about Santorum's Ohio paperwork problems broke on Friday, Santorum's spokesman sought to link the Ohio filings issue to his inability to split the delegate tally in Michigan as evidence that the Romney-led Republican establishment wants to torpedo his campaign.
Santorum, in his comments to reporters, instead said any problems arose from running a campaign with limited resources that had to carefully choose where to concentrate its efforts. In particular, he cited Iowa, where he ended up narrowly prevailing over Romney in January.
"We weren't in a position as Gov. Romney is, as a front-runner and with a lot of resources," he said.
The delegate issue appears headed for a potential legal battle. Ohio Attorney General Mike DeWine - Santorum's leading Ohio backer - told The Plain Dealer of Cleveland that voters likely would be incensed about not having their choices count.
"If he wins the congressional district, who or why would anyone deny him?" asked DeWine, according to the newspaper. "It would be unjust. I just can't see taking it away from the voters. People will be mad and outraged if they wouldn't get what they voted for."
Another of Santorum's rivals, Newt Gingrich, already has indicated he sees a possible opportunity to collect more delegates for himself.
"We want to get as many delegates as we can, and obviously we see real opportunities here," said Gingrich as he campaigned in Hamilton, Ohio. "We think in a number of places where we have filed delegates and some other folks haven't, and so we have a chance to actually pick up a good number of delegates."
Ohio Republican officials said the party has been reviewing its bylaws and are prepared to convene what it calls "a committee on contests" if required. That panel would make a recommendation to the state party's central committee. If Santorum or another candidate was unhappy with the ruling, he could appeal to the Republican National Committee.
Ben Ginsberg, the Romney campaign's national counsel, told reporters that in failing to file appropriate paperwork to appear on the ballot in Virginia and Washington, D.C., as well as various districts in Ohio, Tennessee and Illinois, Santorum is automatically ineligible for 64 of the 391 delegates --16 percent -- up for grabs on Super Tuesday.
Ginsberg also said that, unlike Santorum, former GOP candidates Jon Huntsman and Rick Perry had been able to successfully navigate the process in some of those states before bowing out of the race.
Santorum's inability to turn out the numbers he needs shows deep-rooted organizational deficiencies that "should give Republican voters great pause," said Ginsberg.
Ohio in particular has become a fierce battleground for Romney and Santorum leading up to Tuesday, with Santorum possibly ineligible for 18 of the 63 delegates at stake. He failed to file to receive any delegates in Ohio's 6th, 9th and 13th districts, and only has incomplete filings in other districts. The state has 16 districts.
But even beyond Super Tuesday, Romney political director Rich Beeson said in a memo, Santorum is in trouble in states that award all of their delegates to the primary or caucus winner.
"Rick Santorum can point to states in April and beyond that are permitted to award delegates "winner take all," but many of these states are not friendly territory for him - Delaware, New Jersey, and Utah are just a few examples," Beeson said.
Two other Romney backers on Saturday's conference call -- Rep. Mike Turner, R-Ohio, and Hamilton County Commissioner Greg Hartmann - said the Santorum campaign's struggles would cost dearly if he is to be the general-election nominee against President Obama, whom Hartmann said has "one of the best, most well oiled machines we've ever seen in politics."
Sarah Huisenga and Rebecca Kaplan contributed