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After a series of primary losses Sen. John McCain said it's time for Rick Santorum to make a "graceful exit" from the presidential race. McCain himself set a dignified example when he bowed out in 2000 and then again on election night in 2008 when he acknowledged then President-Elect Obama's perseverance and pledged "to do all in my power to help him lead us through the many challenges we face."

Another example of a poised departure Santorum could look to? Al Gore in 2000 after the Supreme Court sided with George W. Bush. Gore accepted the "finality of this outcome" and offered his concession because "disappointment must be overcome by our love of country."

But I believe Rick Santorum is thinking more along the lines of Ronald Reagan during the 1976 Republican convention. Following a string of victories leading into the convention Reagan finally conceded with a speech that laid the groundwork for his presidential campaign four years later.

But here's the problem for Santorum - Reagan was gaining strength leading into the convention while Santorum is losing his momentum. Santorum is banking on his home state of Pennsylvania to come through for him on April 24, but a new poll out this morning shows that Mitt Romney has pulled ahead.

The best thing for Santorum is to find a way to get out in the next week or two. I think Pennsylvania should and likely will be his last primary. And if he wins his home state that could be another "graceful" way for him to get out of the race. Take the win as vindication after his 2006 Senate loss, take the gains he has made in his presidential campaign but don't continue through the month of May.

My Bottom Line: That is the best way for Santorum to be a viable candidate in four years if Romney doesn't win in November.