If the GOP were to pick up nine seats and neither Ben Nelson nor Joe Lieberman could be lured across the aisle, that would tie the Senate at 50-50. That last happened after the 2000 election (before Jim Jeffords of Vermont crossed the aisle in the other direction a few months later and gave the Democrats a 51-49 majority). In 2001, that meant that Vice President Dick Cheney was the deciding vote on how the Senate would be organized. Now it would be Joe Biden. It would also mean that Biden would have to stick pretty close to home while the Senate was in session to be available to break any ties. Whether that would be a net plus or minus for the Republic, I know not.
But how likely is it that Lieberman or Nelson would switch? I agree with James Taranto that it’s not likely.
And then there’s Alaska. It’s now a Republican seat, but the current holder, Lisa Murkowski, lost the primary and decided, in a fit of chutzpah, to run a write-in campaign. Some polls show her ahead, but do they have any predictive value? I doubt it. I think a lot of people who told the pollsters they were voting for her will, on arriving at the polling booth, decide a write-in vote is just too much trouble and vote for Joe Miller. Even if she wins, I imagine that she would caucus with the Republicans, despite the fact that she was roundly denounced by her Republican colleagues for not accepting the results of the primary and thus putting the seat in jeopardy by splitting the vote. If that were to happen, and the Democrat were to win thanks to Murkowski’s ego, thereby depriving the Republicans of the majority, I don’t think that Murkowski will be invited to many future Republican picnics.