Only in Washington: Republicans need 50 seats to retain control of the Senate in today's elections, but Democrats must have 51 to take it away.
The Constitution, the calendar, the presidential election and a political power play in Massachusetts combine to make it so, a curiosity that gives Republicans a margin for election error that Democrats lack.
"If President [George W.] Bush and Vice President [Dick] Cheney are re-elected, if the Senate is 50-50, the Republicans would maintain control" by virtue of Cheney's ability to break a tie, said Betty Koed, assistant Senate historian.
Even if Kerry wins the White House, she said in a recent interview, "the Republican vice president would be breaking the tie" from Jan. 3, when the Senate convenes, until 17 days later, when the White House shifts hands with the swearing-in of the next president.
By then, Koed said, Kerry would have to resign his Senate seat to take the oath of office as president. Once again, Democrats would be shut out of the majority in the Senate, left with 49 seats to 50 for the Republicans.
Barring the unexpected, it would stay that way until spring or summer. That is when Massachusetts voters would replace Kerry under a law approved by the Democratic-dominated legislature. State lawmakers acted to block Republican Governor Mitt Romney from naming a fellow party member to the seat.
The current Senate has 51 Republicans and 48 Democrats. The 100th senator, Jim Jeffords, is an independent from Vermont who sides with the Democrats for organizational purposes.
"We've got huge momentum. You can feel it in all of our Senate races," Majority Leader Bill Frist, a Republican, said on ABC's This Week. "We'll pick up Senate seats."
In all, there are 34 Senate races on the ballot on Tuesday, only nine of them viewed as competitive by strategists in the two parties. Democrats must win six to move into a 50-50 tie, and seven to win an outright majority. Senators serve for six years.
Most incumbents in both parties are coasting to new terms after campaigns in which they drew little-known and poorly funded rivals.
Idaho Senator Mike Crapo, a Republican, arguably has the easiest time. His only opponent is a write-in, Democrat Scott McClure.