Paul Ryan gave a great speech last night with a flaw that might bite him: He was misleading. 

The speech itself was full of great lines and added up to the best  thematic takedown yet of President Obama. Ryan played to Obama's Achilles heel: the loss of hope. The line about college graduates living out their 20s in their childhood bedrooms staring at old Obama posters was a classic. And Ryan handled his critique of Obama well; he didn't blame him for creating the problems, just for making them worse.

But Ryan also created a problem for himself with the speech. As Joan Walsh points out, he said some things, such as about a GM plant closing in his district under Obama, that aren't true, and some other things that are misleading even by today's fallen political standards. The president may have punted on the Simpson-Bowles debt commission, but Ryan voted against the recommendations as a member of it. Ryan's attack on Obama's Medicare "raid" neglected to mention that the congressman himself voted to cut Medicare by $716 billion. Or that the downgrade in the nation's credit status was the direct result of Ryan's "young guns" refusing to help House Speaker John Boehner compromise with the president.

Things move on in politics, but they also come back around. When Chris Christie left the convention  hall Tuesday, early reviews of his speech were okay to good. But yesterday, the conventional wisdom shifted, and the speech is being widely panned.  Today, presumably any doubts about Ryan will be swept away in anticipation of one of the more important political speeches in many years: Mitt Romney's. But Ryan may have planted some bad seeds for himself.