Senator Pete Domenici (R-NM) is expected to announce tomorrow his retirement from the U.S. Senate, creating another plum pickup opportunity for Democrats. At the front of the pack of likely contenders is Rep. Tom Udall, who already has a fat bank account and is the target of a draft effort, following the leaked news that Domenici is expected to depart the Senate.

A retirement in the Senate is interesting enough, but the possibility of a Tom Udall candidacy is fascinating for another reason...
Tom Udall's cousin Rep. Mark Udall is already running for the U.S. Senate. So we've got two cousins and two Udalls possibly running, both as Democrats.

But it gets stranger. Incumbent Senator Gordon Smith (R-OR) is also a member of the Udall family, a second cousin of both Udalls. Even stranger, they're double cousins twice. How's that work? The respective predecessors involved two pairs of siblings that intermarried.

Senator Smith is facing a tough re-election effort in 2008. The Colorado Senate race is considered a top tier race. And if Tom Udall jumps into the New Mexico campaign, it will immediately become a top tier pick-up opportunity. And that's how three cousins could end up in the three most competitive U.S. Senate races West of the Mississippi.