By STEVE PEOPLES and KASIE HUNT
GREEN BAY, Wis. - As Mitt Romney looked for a sweep in Tuesday's three Republican primaries to tighten his grip on the party's nomination, President Barack Obama criticized the GOP front-runner by name in a campaign ad for the first time, signaling that he too thinks the nomination race is all but over.
Regardless of the outcome in Wisconsin, Maryland and Washington, D.C., Romney was rapidly shifting toward the general election _ and the challenges of Obama's better-financed and better-organized opposition.
The president flexed that campaign muscle Monday, suggesting that he's ready for Romney even if the former Massachusetts governor isn't quite ready for him. Obama released a television ad set to run in six swing states accusing Romney of standing with "Big Oil." The ad came hours after the release of a similar campaign from an Obama ally.
Romney has been ignoring his Republican rivals for several days and taking it to the Democratic president, whom he accused Monday of "crushing dreams" with a "government-centered society."
"He takes his political inspiration from the capitals of Europe," Romney told supporters in Green Bay, Wis., one day before the latest primaries in the GOP fight. "His version of a perfect world is a big-spending big government."
The grinding Republican primary, already 3 months old, has complicated his ability to re-focus his broader organization and resources toward Obama. Aides concede that staff building and fundraising for the fall match-up are lagging.
Romney's recent string of high-dollar California fundraisers was limited to raising money only for the Republican primary contests. Aides are only beginning to take steps to raise cash to use against Obama, who has been aggressively fundraising and distributed staff on the ground in almost every state in the nation.
The delay has given Obama a massive head start. The disparity is staggering.
At the end of February, Obama reported $84.7 million in his campaign account compared to Romney's $7.3 million. Obama has more than 530 paid staff compared to roughly 100 for Romney.
A fading Rick Santorum, also campaigning in Wisconsin on Monday, said that Romney has essentially bought his success by outspending the competition.
Romney and his allies have spent a combined $53 million on television advertising so far this election cycle compared to just $27 million from his three Republican competitors combined, according to data compiled by the media tracking firm SMG Delta.
Santorum's team, having narrowly lost a string of high-profile contests, spent just $9 million.
"With almost unlimited resources, Gov. Romney has not proven to be very effective," Santorum said Monday as he predicted a possible upset in Wisconsin. "The only way he's been successful in winning the primaries is by just bludgeoning his opponents by an overwhelming money advantage _ something he's not going to have in the general election."
In the primary race, Romney has a huge advantage in delegates. On Monday, The Associated Press count had Romney with exactly half the delegates needed to win the nomination, 572, and twice as many delegates as Santorum.
For the fall campaign, Romney's presidential hopes may rest, at least in part, upon the ability of the Republican National Committee to give him a running start. The RNC, beset by problems of its own in recent years, says it's ready to meet the challenge. Yet party officials acknowledge limitations. General election fundraising in particular has suffered without a nominee.
The RNC last week announced it had filled a "presidential trust" with $21 million to spend in coordination with the nominee. But there is no limit on what the committee can raise and spend on its own to support the party's presidential contender.
"There are donors that are sitting on the sidelines right now," said RNC political director Rick Wiley.
Romney's campaign has also been anxious to be able to raise money for the party itself when it holds finance events _ donors can cut checks of up to $30,800 to the party committee. But without the nomination, they haven't been able to ask for that money yet.
The complications extend beyond fundraising.
Wiley said the committee's nationwide network of "victory centers" might not be fully operational until August unless a nominee secures the nomination soon.
"I think you will see as soon as you get a nominee, an accelerated ramp-up of staff," Wiley said. "Right now everyone's out the door by August, but I can see a scenario where everyone was out the door by June or July if we had a nominee in the next 30 days or so."