The Republicans had the misfortune (or lack of common sense) to have their more defective Senate candidates in winnable states and some of their better choices in harder-to-win locales. Sen. Scott Brown (R-Mass.) is not likely to pull out a win, especially with the top of the ticket running far behind the president. In Maine, Republican Charles Summers has run a strong race, but absent a huge GOP sweep nationwide, the political environment in Maine is likely too treacherous.

That puts the Republicans down two seats. Todd Akin has likely punted away a possible pick-up, while Richard Mourdock has only a slim chance to hang on (hoping Mitt Romney victory is oversized and sufficient to pull him along). Republicans could very likely be down three seats from these races.

On the positive side, Tommy Thompson, if Romney pulls out a win on the strength of the Scott Walker recall ground game, could well squeak through. Unexpectedly tough races in North Dakota and Montana will in the end fall to Republicans, I suspect, in part because Romney will win both states handily. Those wins would pull Republicans even in Senate seats.

Then we go to tougher races in Connecticut, Virginia, Ohio, and Florida. Linda McMahon has the toughest of these and is not likely to pull an upset. Connie Mack IV’s chances rest nearly entirely with a comfortable win, which could well occur based on recent polling and early voting returns. Ohio and Virginia will be close, as will the presidential races. I don’t see many Obama-Josh Mandel voters or Obama-George Allen voters. So, if Romney wins both states, his Senate compatriots could well pull out narrow wins. That gives Republicans potentially two more seats.

For the upset of the night I’ll take Tom Smith in Pennsylvania who has run against the lousy, boring campaign of Sen. Bob Casey, Jr., who is regarded by many swing voters as a do-nothing insider riding on his daddy’s coattails.

That would leave Republican with a net gain of three seats, and a 50-50 tie in the Senate. In both the outcomes of individual races and in the identity of the tie-breaking president of the Senate (the vice president) the presidential race will, I suspect, go hand-in-hand with the control of the Senate.