Like Stu Rothenberg (“States that historically have been competitive in presidential elections or tilted to the GOP are moving in that direction, even though just a month ago they were favoring Barack Obama”) I see momentum on Mitt Romney’s side in the presidential race. However in the Senate it appears increasingly unlikely that Republicans will get a majority, and they might not even pick up very many seats. So far the only certain pick up seems to be in Nebraska, where Deb Fischer seems to be cruising to victory.

However, other strong pick-up possibilities ( North Dakota, Montana, Virginia) are neck and neck. Meanwhile, Todd Akin’s debacle is likely to cost the GOP another pick up. Richard Mourdock has managed to make Indiana a possible Democratic pick-up. In Maine, Angus King is leading handily, meaning another GOP seat loss. And in Massachusetts, Sen. Scott Brown (R-Mass.) is trailing Elizabeth Warren and will face Election Day headwinds with the Republican top of the ticket trailing Obama by double digits. Florida, once thought to be a good opportunity for the Republicans, is increasingly looking like a hold for the Democrats. Tammy Baldwin is narrowly ahead in Wisconsin, potentially blocking another pick-up chance. Ohio is a dog fight, not unlike the presidential race, which could well leave the Democrats with that seat.

Two feisty Republican challengers are making a go of it in in the Northeast. In Connecticut, Linda McMahon is a smidgen back, and self-funder Tom Smith is in a statistical tie in Pennsylvania. Both could be pick-ups for the Republicans.

On Election Day, if Romney runs well across the country, it is certainly possible that Nebraska, North Dakota, Wisconsin, Montana, Virginia, Ohio and Pennsylvania fall into the GOP’s lap while Mourdock holds on along with Republicans in Nevada and Arizona. With losses in Missouri, Massachusetts and Maine, that best-case scenario would yield a pick-up of five. You won’t find many Republicans willing to bet on that result, however. It seems far more likely that Republicans will pick up many fewer than six seats, lose Maine and Massachusetts, and fritter away Missouri. In other words, Republicans might not pick up very many seats at all.

Why are Republicans having such a hard go of it? RNC officials and Republican third-party groups have uniformly told me over the past few days that the answer is “candidate selection.” The Republicans, not unlike in 2010, are stuck with some contenders (Mourdock and Akin, most obviously) who are “not optimal.” Privately, Republicans will say that Tommy Thompson in Wisconsin and George Allen in Virginia are running lackluster races, allowing extremely liberal opponents to paint themselves as middle-of-the-road Democrats. What strong candidates there are meanwhile — in Massachusetts and Maine — simply face near-impossible odds in heavily Democratic states.

If in two consecutive elections Republicans blow the chance to take the Senate, there will and should be some soul searching. Republican primary voters are ultimately responsible for selecting candidates who don’t hold up to scrutiny in a general election, but the critical process of finding and cultivating young talent is a party function that (unlike efforts on the House side) haven’t amounted to much. If Republicans are ever going to take the Senate, of those will have to change.