* THE FINAL FORECASTS: The HuffPollster model puts the odds of a GOP Senate takeover at 79 percent. FiveThirtyEight puts it at 76.2. And the New York Times’ Upshot hast it at around 70 percent.

* THE FINAL POLLING AVERAGES: In Colorado, Cory Gardner leads Senator Mark Udall by 1.9 points. In Georgia, David Perdue leads Michelle Nunn by four points, but he appears short of the 50 percent to avoid a runoff. In Iowa, Joni Ernst leads Bruce Braley by 2.4 points.

In New Hampshire, Senator Jeanne Shaheen leads Scott Brown by 1.4 points. In North Carolina, Senator Kay Hagan leads Thom Tillis by 0.7 points. In Kansas, Senator Pat Roberts leads independent Greg Orman by 1.7 points.

All these races could still go either way, but the big picture remains that Republicans lead by more than four points in enough states to take the majority.

* UNCERTAINTY REMAINS IN THE POLLS: Nate Silver explains how lingering uncertainty in the polls means the possibility of Democrats holding the Senate cannot be ruled out entirely. There are two scenarios, one in which they are close to right, and one in which they are wrong:

In the final set of simulations we ran, Democrats won just 14 percent of the time when the overall bias in the polls was less than one point in either direction. This represents what we’ve called the “squeaker” scenario — Democrats eke out victories in just enough of the competitive states to win, even though the polls do a reasonably good job overall. The Democrats’ alternative is the “shocker” scenario — the case where the polls do prove to be skewed against them. In the simulations where the polls had at least a 1-point Republican bias, Democrats won the Senate 61 percent of the time.

So if the polls are a bit off, Democrats can hold. Of course, they could beunderestimating GOP strength, which would mean a bigger-than-expected GOP majority.

 * HOW OLD WILL TODAY’S ELECTORATE BE? Gerald Seib notes that today’s outcome will be determined in part by which side shapes the electorate they want, and offers this polling:

When Journal/NBC News pollsters gauged which voters are likely to actually show up to cast votes, based on their interest in this year’s election and their voting history, they found that just 11% of those most likely to vote this year are under the age of 30. Meanwhile, a hefty 24% of those most likely to vote were those aged 65 and over…it will be a much older electorate overall than the one that showed up for the 2012 presidential election.

Morning Plum polling has found similar disparities, and indeed, this problem has shown up in polls as far back as the spring. Today will determine whether Dems are putting any kind of dent in it.

* OTHER STORIES TO WATCH TODAY: Danny Vinik has an important reminder: The Medicaid expansion and the minimum wage are also on the ballot today in multiple states. If Democrats or independents are elected governor in a number of states, it could result in an expansion of health coverage under Obamacare’s Medicaid expansion. Meanwhile, voters in four states will weigh in on whether to raise their states’ minimum wage.

So even if Democrats lose the Senate, there could be some bright spots for the Democratic agenda here and there.

* WE’RE PROBABLY HEADING FOR RUNOFFS, FOLKS: The Post has an overview of all the plans outside groups are already putting together in the event that Senate control could be decided by runoffs in either Louisiana or Georgia, or both.

If this comes to pass, either one or both states will be absolutely flooded with outside money, political operatives, party lawyers, and preening national media figures. My God, what a zoo that will be.