The wise folks at FiveThirtyEight.com report that there's a 64.5 percent chance of the Republicans gaining control of the United States Senate next year. Let's assume that happens.

What next? Over the previous six years, one could rarely go wrong predicting that congressional Republicans would choose the more confrontational, at times really dumb option in any situation. To be honest, I don't expect that to change if voters give them control of both chambers of Congress. Quite the contrary.

Take the matter of nominations. With the Senate in GOP control, one of two things would have to happen: Either a handful of Senate Republicans would have to vote to confirm Obama nominees, exposing themselves to attacks from within a party for whom unity is a primary virtue, or no nominees for the executive or judicial branches will be confirmed in the rest of Obama's term.

That latter outcome would certainly please the GOP base, which has long sought all-out confrontation with Obama; the question is what impact such a strategy would have on moderate and independent voters who may not necessarily be thrilled with Obama, but who still see value in a functioning federal government.

And where might those GOP confirmation votes come from?** Well, of the 34 Senate seats up for election in 2016, 24 are held by Republicans. Of those 24 Republican seats, seven are in states that went for Barack Obama in 2012. Those seven senators might be more inclined than their counterparts to cast votes allowing them to seek re-election as moderates. But again, should they do so, they also make themselves vulnerable to a challenge in the Republican primary.

Tis a conundrum.

With control of both chambers, Republicans also would be forced by their base to vote on a total repeal of ObamaCare, including a repeal of Medicaid expansion that has provided coverage to millions of Americans. (Obama would of course veto the effort.) But based on their record of the last six years, the GOP also would be completely incapable of drafting anything to replace that coverage.  Again, the base wouldn't care, but for everybody else, replacing an arguably flawed approach to health insurance with no approach at all would make the GOP appear destructive, mean-spirited and incompetent.

Again, tis a conundrum.

On immigration, congressional Republicans are even less capable of passing something to deal responsibly with the 10 to 12 million people who are living here illegally and have been doing so for years.  For example, it is almost certain that President Obama will take executive action soon to address that problem, but GOP Chairman Reince Priebus is predicting total, all-out war should he do so. As Priebus promised party activists in a phone call this week:

"We will do everything we can to make sure it doesn't happen: Defunding, going to court, injunction. You name it. It's wrong. It's illegal. And for so many reasons, and just the basic fabric of this country, we can't allow it to happen and we won't let it happen. I don't know how to be any stronger than that. I'm telling you, everything we can do to stop it we will."

GOP policy on immigration is completely in the hands of the most reactionary elements within the party, and despite recognizing the danger, Priebus and other party leaders have been unable to wrest it away. The chances of that changing are near zero, and that will have consequences for the party for at least a generation.

Overall, as we know, Congress is already the least respected institution in America with a 13 percent job approval rating. With control of Congress shared between the two parties, blame for its dysfunction can be shared as well. But with total Republican control would come total Republican responsibility. On the bright side, if McConnell and John Boehner can craft their respective chambers into a well-disciplined, responsible, governing majority, they will get -- and certainly deserve -- all the credit for that unlikely transformation.

if not ....

Finally, the GOP is increasingly reliant on a fast-shrinking share of the electorate. It is telling that Pat Boone, the singer who has been famous for being old-fashioned and out of date for at least a half-century now, has been making robocalls to senior citizens on behalf of Republican candidates around the country, including David Perdue here in Georgia. It's smart:  In the AJC's most recent poll, Perdue was up just two points over Michelle Nunn, and that margin was entirely the product of his 19-point advantage among senior citizens. Getting those people to the polls is essential to Perdue's hopes.

But like so much in the GOP strategy, the sell-by date for that strategy is approaching quickly.

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** That of course assumes that Mitch McConnell, as majority leader, would allow such nominations to even be voted upon. And if a vacancy opens on the U.S. Supreme Court in the next two years .... woo boy. Republicans could block confirmation of an Obama nominee, but at potentially high political cost. They would also have to worry that a new Democratic president elected in 2016 would name an even more liberal nominee for the vacancy, and would have the Senate votes to confirm. Conundrums conundrums ...