The conventional wisdom -- which is sometimes correct -- is that Arlen Specter lost the Democratic Senate nomination in Pennsylvania because he switched parties -- an act of opportunism exploited by his opponent Joe Sestak in a devasating TV ad.

But as someone who covered Specter  for 20 years  as an editorial writer in Pittsburgh, I can say with some authority that the switch-not-in-time was the culmination of a career of playing the angles.

If you're interested in a trip down memory lane, here's a column I wrote about Specter in 2007. The peg was Specter's advice to Sen. Larry Craig after Craig's men's-room embarrassment. (No, it wasn't "Switch parties," but "hang in there.") But I also traced the zigzagging that characterized Specter's fascinating time in public life.