On Friday, President Obama will get the back of someone who's been protecting his from day one. The president will campaign in the 5th congressional district of Virginia--Charlottesville--for Rep. Tom Perriello, a freshman Democrat who has voted with the administration on every issue of significance, including health care reform, the stimulus, and cap-and-trade.

As a reward for his diligence, Perriello has been a top target for Republicans. He's benefiting slightly from the fact that his challenger, State Sen. Richard Hurt, has to deal with a Tea Partier who managed to get a third line on the ballot. But the race is exceptionally close, and Hurt has made it so simply by linking Perriello to the Obama-Pelosi agenda. Perriello does have some independence to show off: he voted against the Wall Street Reform legislation and opposes gun control

Obama's visit tells us several things:

1. He's willing to make Perriello's re-election dependent on replicating the 2008 Obama turnout coalition.

2. The House remains in serious jeopardy for Democrats.

3. POTUS rewards loyalty, and that's something the "professional left" can appreciate.