That may end up being the title of Mark Halperin and John Heilemann’s next book. Yes, as of now the Wisconsin congressman has no interest in running in 2012. But my cardinal rule of politics is never to assume that the future will be a straight-line projection from the present.

In January 2013, when Halperin and Heilemann set down to write this hypothetical book, they will focus on a few key events. The first is Obama’s singling out Ryan during the House Republican retreat in January 2010. That’s when the president elevated Ryan to the level of presidential foil.

Next is the White House health-care summit in February 2010, when Ryan rose to the challenge and eviscerated Obamacare in a few minutes, leaving the president more or less dumbfounded. After that, the narrative will move to the August 2010 Weekly Standard cruise, where Paul Ryan won the informal straw poll.

Halperin and Heilemann will touch on the 2010 election, when the Democrats’ demagogic attacks on Ryan’s Roadmap failed to sway seniors. They’ll write about Ryan’s 2012 budget and how it forced Obama to throw out his original proposal and counterattack. The dueling budgets, they’ll recall, became the poles of the 2012 debate.

Charles Krauthammer’s column today is another important moment:

A remarkable class of young up-and-comers includes Paul Ryan, Chris Christie, Marco Rubio, Nikki Haley. All impressive, all new to the national stage, all with bright futures. 2012, however, is too early — except possibly for Ryan, who last week became de facto leader of the Republican Party. For months, he will be going head-to-head with President Obama on the budget, which is a surrogate for the central issue of 2012: the proper role of government. If Ryan acquits himself well, by summer’s end he could emerge as a formidable anti-Obama.

One problem: Ryan has zero inclination to run. Wants to continue what he’s doing right now. Would have to be drafted. That would require persuasion. Can anyone rustle up a posse?

April 22, 2011, will be known as the day that drafting Ryan in 2012 vaulted into the mainstream. And the posse? I hear it coming.