WASHINGTON -- His delegate lead growing, Mitt Romney's campaign suggested Wednesday that his Republican presidential opponents have no chance to win and should consider dropping out because they're hurting the party's chances of defeating President Barack Obama in November.
Rick Santorum and Newt Gingrich paid Romney no mind, vowing to fight on in a campaign marked by persistent ideological divisions.
If anything, the political maneuvering intensified as the marathon pointed toward contests in five states over the next week. Romney's campaign bought television advertising time in Alabama as it pursued a breakthrough in the party's Southern base, according to campaign sources.
A Santorum ally urged Gingrich to quit the race.
In response, the former House speaker said he would consider it -- if he thought Santorum would beat Romney and then Obama. "I don't," he added.
And when Santorum was informed that an aide to Romney had said it would take an act of God for any other candidate to amass a majority of convention delegates, Santorum responded heatedly.
"What won't they resort to to try to bully their way through this race?" Santorum said in Lenexa, Kan. "If the governor now thinks he's now ordained by God to win, then let's just have it out."
One day after Super Tuesday, Romney's campaign circulated a memo making the case that his six victories on a single night have increased his delegate lead to the point that any of his rivals will have a hard time catching up. And they are hurting the party by continuing to try, it suggested.
"As Gov. Romney's opponents attempt to ignore the basic principles of math, the only person's odds of winning they are increasing are President Barack Obama's," it said.
Romney didn't go that far in an interview, and he stopped short of a flat prediction that he will achieve his goal of a pre-convention delegate majority.
"We think that will get done before the convention, but one thing I can tell you for sure is there's not going to be some brokered convention where some new person comes in and becomes the nominee," he said on CNBC's Squawk Box.
After Super Tuesday, Romney has 419 delegates overall, more than his three rivals combined. Santorum is second with 178, Gingrich has 107, and Paul has 47. It takes 1,144 to win the nomination.
While Romney clearly would like all his opponents to drop out, the departure of just one -- Santorum or Gingrich -- might be less welcome. The two often divide the anti-Romney vote and let him win contests he might otherwise lose.
In Ohio, Tuesday's marquee matchup, Romney edged Santorum by a little more than 10,000 votes out of 1.2 million cast. Gingrich drew about 175,000 votes and Ron Paul 111,000.
Gingrich and Santorum argue that despite Romney's financial and organizational advantages, he came late to conservative causes, is plagued by inconsistencies in his record and is unable to articulate significant differences with Obama.
This week, Romney abruptly abandoned a position he has held since he ran for governor to link increases in the federal minimum wage to rises in inflation. He had reaffirmed it as recently as last month, telling reporters, "I haven't changed my thoughts on that."
But Santorum and Gingrich hold opposing views, as do Republican business allies. On Tuesday, Romney said on CNBC, "There's probably not a need to raise the minimum wage."
In a post-Super Tuesday interview, Romney also said there is no current way of proving that his proposed tax cuts wouldn't raise the deficits, "because those kind of details have to be worked out with Congress and we have a wide array of options."
He has called for a 20 percent reduction across the board in personal income tax rates and said he would recommend curbing some of the existing breaks that wealthier taxpayers enjoy. Asked what level of income would qualify as wealthy, he sidestepped.
"What I'll look at is the various cohorts, the top 5 percent, the top 10 percent, the top 25 percent. We'll look across the code at the various categories and see if they're continuing to pay the approximate share that they've paid in the past under the current system," he said.
Next up: Kansas
Santorum campaigned in Kansas, which holds caucuses Saturday with 40 delegates at stake. Wyoming, with 12 delegates, is also on the calendar, as are the Virgin Islands, Guam and the Northern Mariana Islands, with six each.
The former Pennsylvania senator won three Super Tuesday states, reviving his campaign, and he issued a fresh appeal for campaign funds to compete with Romney.
"We've proven we can win this race. ... I think this is because Americans are looking for a blue-collar Reagan conservative -- not a Massachusetts moderate," the appeal said.
Tuesday's calendar runs from primaries in Alabama, 47 delegates, and Mississippi, 37 delegates, to caucuses in Hawaii, 17, and American Samoa, six.