ABC's Chris Good and Michael Falcone report:

With their win in Illinois on Tuesday night, Mitt Romney's campaign is more openly suggesting that Rick Santorum, Newt Gingrich and Ron Paul take a page from Romney's 2008 playbook and drop out of the race.

Romney strategist Eric Fehrnstrom, in an interview with CNN's Piers Morgan, said that even though John McCain had not yet clinched the Republican nomination at a similar point in the race four years ago, Romney "made the decision - and it was a difficult one - to step aside."

In 2008, Romney quit the race "because he thought it was good for the country," Fehrnstrom said, and because "he wanted to give John McCain the time to rally the party and unite behind his candidacy." He added that this year,  "there is no deus ex machina that's coming down from the heavens that's going to change the math of the race."

So, was Fehrnstrom's comparison of the 2008 and 2012 races accurate?

When Romney exited the race in 2008, his delegate math looked a lot like Santorum's does today. Santorum has collected 22 percent of the delegates needed to win the nomination, while Romney had collected 24 percent in 2008.

Upon Romney's 2008 exit, fewer than half (44 percent) of all delegates remained to be allocated, either in upcoming states or as RNC superdelegates. After the 2012 Illinois primary, just over half (53 percent) will be elected by remaining states or sent to Tampa as superdelegates.

McCain, however, was mathematically closer to the Republican nomination than Romney is today.

Romney dropped out on Feb. 7, 2008, two days after Super Tuesday in that year's front-loaded primary schedule. At the time, John McCain had won over 630 delegates, nearly 60 percent of the 1,191 delegates needed to win the nomination. With delegates still being tallied in Illinois, Romney has won 560 - just fewer than half (49 percent) of the 1144 needed to win in 2012.

In other words, Romney is close to where McCain was in 2008 - but he's not quite there.

Here's the full exchange between Piers Morgan and Eric Fehrnstrom:

PIERS MORGAN:  "Is it time seriously for Newt Gingrich and/or Ron Paul or both of them to consider stepping down?"

ERIC FEHRNSTROM: "Look, that's a very personal decision. I'm not going to make that for them. I understand about the emotion and the hard work and the sweat that goes into a campaign, they have been at it for a long time. Both Rick Santorum, Newt Gingrich and Ron Paul - they're decent people. They have run honorable campaigns. At some point the reality is going to set in that Mitt is the all but certain nominee. I can tell you what Mitt Romney did four years ago when he found himself in the similar situation running against John McCain. After Super Tuesday, John McCain certainly didn't have the delegates to become the nominee, but he was on track to get those delegates and Mitt Romney made the decision - and it was a difficult one - to step aside. And he stepped aside because he thought it was good for the country. We were at war in Iraq at the time, and he wanted to give John McCain the time to rally the party and unite behind his candidacy."

MORGAN:  "Well, from what you're saying, are you suggesting that they all should stand aside now? Is tonight a tipping point do you think in this race? Should all three of the candidates, given the number of delegates your man has, should they stand aside? We've got 20 seconds."

FEHRNSTROM:  "Well, there is no deus ex machina that's coming down from the heavens that's going to change the math of the race. Look Mitt Romney has the most delegates. The reason he has Mitt Romney has the most delegates is because has the most votes and the reason for that is because he has the best pro-jobs message. Each candidate will have to make these decisions on their own."