WASHINGTON — It hasn’t been pretty, but the Republican establishment, the delegate math, the money and more are increasingly lining up in Mitt Romney’s favor in the long and grinding race for the party’s presidential nomination.

The race will go on. Romney’s most dogged rival, Rick Santorum, is all but certain to claim more victories before the primary season ends.

And an astonishing admission Wednesday by one of Romney’s top aides — that primary-season policy positions may be no more lasting than squiggles on a child’s Etch A Sketch drawing toy — will hardly reassure Republicans skeptical about his commitment to the cause of conservatism.

“Everything changes” for the fall campaign, said Eric Fehrnstrom, prompting Romney himself to try and limit the political damage. “The policies and the positions are the same,” he said.

Still, Romney’s Illinois primary victory provided fresh evidence of electoral strength, produced a big delegate haul and paid an overnight dividend in the form of an endorsement from Jeb Bush.

“Now is the time for Republicans to unite behind Governor Romney and take our message of fiscal conservatism and job creation to all voters this fall,” said the former Florida governor, the man most often mentioned as a last-minute savior for the party, who could swoop into a deadlocked convention and emerge with the nomination.

Former Sen. Bob Dole, a Romney supporter, summarized Santorum’s position from the point of view of a man who lost his first try for the nomination before winning on the second.

“In every race, Romney is going to pick up delegates. Looking back at my race in 1988 … I should have gotten out, but I just kept going out there,” Dole said. “When you’re out of money and you don’t have the organization to buy TV, you have to take a hard look at it. As much as you don’t want to do that, sometimes you have to face reality.”

Much has changed since Dole last ran for the White House in 1996, including the emergence of super PACs that are allowed to raise money in unlimited amounts. That, too, is working to Romney’s advantage.

So far, he has benefitted from more than $32 million in television ads from Restore Our Future, the entity that played the major role in wiping out Newt Gingrich with attack ads in the days before the Iowa caucuses and again in the Florida primary. More recently it has turned its attention to Santorum.

For comparison purposes, the $32 million is more money than Santorum, Gingrich and Ron Paul plus super PACs supporting them have spent combined on television, and may be the reason Romney has been able to avoid dipping into his own personal fortune so far in the campaign.

Additionally, campaign finance reports released Tuesday showed that big donors to a GOP organization founded by political strategist Karl Rove have boosted their financial support for the Romney-aligned super PAC in recent months.

It’s taken months, far longer than anticipated, for Romney to begin to take charge of a race that he began with overwhelming financial and organizational advantages. His record as a Massachusetts governor, particularly his embrace of a requirement for state residents to purchase health insurance, has made it hard for him to win over doubting conservatives in the South and elsewhere.

“Ann drives a couple of Cadillacs,” he blurted out in one appearance, one of several utterances that suggest he doesn’t quite understand the financial woes facing millions of Americans in the wake of the worst recession in decades.

Yet in Illinois, he won more votes than Santorum and Gingrich put together, a far better showing than the grudging victories he eked out in Michigan and Ohio over the previous few weeks.

Romney’s delegate haul was even more impressive. He picked up 41, to 10 for his chief rival. That was hours after an aide to Santorum went on television to predict that the former Pennsylvania senator would win between 24 and 30.

There were more embarrassing moments for the former senator’s campaign. The candidate himself backpedaled after saying on Monday that the economy wasn’t the main issue of the campaign. “Occasionally you say some things where you wish you had a do-over,” he said later.

The calendar, too, is a problem for Santorum, his objections aside.

In a memo released March 11, his campaign said Romney’s claims of delegate superiority were based on “fuzzy math. … Simply put, time is on our side.”

In the days since, Romney has won 109 delegates, Santorum 44.

In The Associated Press count, Romney has 563 of the 1,144 delegates needed to clinch the nomination at the convention in Tampa, Fla., next summer. Santorum has 263, Gingrich 135 and Paul 50. That gives the front-runner more than half, a pace that will let him seal his victory by the time the primaries end on June 26.

Past performance is no guarantee of future results, and Santorum has every reason to anticipate victory on Saturday in Louisiana and elsewhere.

Yet the mid-range forecast is less than sunny for him.

He is not on the ballot in Washington D.C., effectively conceding 16 delegates in one of three primaries on April 3. Restore Our Future is already advertising on television in Maryland, the second of that night’s three contests.

Wisconsin, the third, is likely to be the next big showdown. Restore Our Future has already sunk $2.3 million into TV advertising in the state, getting the sort of head start that helped Romney come from behind in Michigan and Ohio, and prevail in Illinois. Santorum has so far spent about $50,000.

Then comes a three-week break, followed by primaries in Connecticut, Delaware, New York, Rhode Island and Santorum’s home state of Pennsylvania. If Romney and Restore Our Future challenge him there in Pennsylvania, he will be stretched to mount much of a campaign in the other states.

“Saddle up,” Santorum exhorted his supporters on Tuesday night after losing Illinois. He spoke not far from the historic battlefield at Gettysburg, Pa., where the tide turned decisively toward the better-equipped and financed Union in the Civil War.

“We’re almost there,” said Romney.