The contest for the seat held by Sen. Jon Tester, a Montana Democrat, is one of the potentially close 2012 races that could ultimately decide whether Democrats maintain control of Congress' upper chamber.
As such, the battle is attracting attention from outside groups hoping their financial assistance will make a difference for both the first-term Democrat and his Republican challenger, Rep. Denny Rehberg, the state's sole House member and a former lieutenant governor.
In election season, conventional wisdom holds that a costly, drawn-out primary fight hurts a nominee in the general election.
It's a notion that appeals to common sense. After all, the thinking goes, if a boxer endures nine rounds with a formidable challenger and immediately steps back into the ring with a well-rested heavyweight, that can't be good.
Comedy Central's Stephen Colbert is running for president. He's parodying the process — including, now, superPACS — in the same way he has parodied cable news. He's getting plenty of attention, but to really look into his political practical joke, I needed to go upstairs and find Peter Overby, NPR's man on campaign finance. I warned him it would seem like a dumb question, but I needed his help. What, exactly, is a superPAC?