All three major Senate models are virtually unchanged from one week ago, meaning that Republicans continue to hold a better than six in 10 chance of winning the majority in eight days.

Election Lab, The Washington Post's model, remains -- as it has the entire cycle -- the most bullish on Republicans' prospects, pegging that possibility at 92 percent. LEO, the New York Times model, puts the chances at 68 percent, while FiveThirtyEight's model gives Republicans a 63 percent chance. In each case, the chances of a Republican takeover are within a percentage point of where the models put them last week.

All three models give Republicans a better than 75 percent probability of winning six seats that Democrats control: in Arkansas, Colorado, Louisiana, Montana, South Dakota and West Virginia. Two more Democratic seats -- in Alaska and Iowa -- have a 65 percent to 75 percent probability of a GOP takeover.  The best Democratic takeover chance is in Kansas, where FiveThirtyEight and LEO give Greg Orman, who is running as an independent, a slightly better than 50-50 chance of beating Sen. Pat Roberts (R). But, Orman has not made clear which side he will caucus with if he wins -- so calling it a Democratic "pickup" is a bit dicey.

The biggest movers in a week in which there wasn't much movement?

For Democrats, it's Georgia -- the open seat held by Sen. Saxby Chambliss (R) -- where Michelle Nunn (D) is looking stronger and stronger as a potential upset winner. Election Lab now gives Nunn a 55 percent probability of winning, while LEO (53 percent) and FiveThirtyEight (51 percent) still tilt ever so slightly toward businessman David Perdue (R). It's worth remembering that Georgia has a runoff provision, meaning that if neither Nunn nor Perdue get 50 percent of the vote on Nov. 4 -- a possibility with a third-party candidate in the race -- the duo would advance to a Jan. 6 (yes, you read that right) runoff.

For Republicans, it's Colorado, where Rep. Cory Gardner (R) continues to pick up momentum in the race against Sen. Mark Udall (D). Two weeks ago, LEO and FiveThirtyEight gave Gardner a 57 percent chance of winning. Now FiveThirtyEight is up to 77 percent and LEO is at 82 percent. Election Lab, which put Gardner's chance of victory at 80 percent two weeks ago, now pegs it as a 95 percent likelihood.

Republicans would gladly take one more week of the status quo. If nothing changes between now and Nov. 4, they will retake the Senate majority.