The news that Wisconsin Rep. Paul Ryan is considering a run for president in 2012 threatens to further shake up an already volatile field on the Republican side — though most plugged-in GOP observers regard a bid by the Wisconsin Republican as very unlikely. The Weekly Standard’s Steve Hayes — a Fix friend — reported this morning that Ryan was debating the possibility of a bid and quoted a GOP source close to the Congressman saying that “he’s coming around” on the idea. And, last night former Bush White House political strategist Karl Rove told Fox News Channel’s Sean Hannity that Ryan as well as New Jersey Gov.