Senate forecast 10/17/16

So I decided to look into how the senate is doing, and I'll do an analysis similar to what I do for president.

A close race

According to RealClearPolitics (where I get my polling data from), we're looking at a very close race. We have 45 safe seats for the democrats and 46 safe seats for the republicans. 9 Races are in the air. 

Florida - 4.7% R

Illinois - 7.0% D

Indiana - 3.5% D

Missouri - 2.3% R

Nevada - 2.0% D

New Hampshire - 1.8% R

North Carolina - 1.8% R

Pennsylvania - 0.4% D

Wisconsin - 3.0% D

That being said, it looks like the most likely scenario for the senate is a straight up tie. 50-50. The democrats win 5 of the swing races, and the republicans win the other 4. It looks like the most shaky race seems to be here in Pennsylvania, between wishy washy centrist McGinty (yuck!, and yes, I must give my opinion here as a progressive Pennsylvanian) and bat**** crazy Toomey. Ugh, guess I'm gonna vote for the lesser of two evils there. I shouldn't blame McGinty for my beefs with the presidential election anyway I guess. I also don't think there's a third party candidate running amenable to my views, so...yeah. Might as well vote democrat there.

Anyway, in order to tip the senate to the republicans, all they have to do is win the four states they're supposed to and win PA. This would be an R + 0.4% situation. In order for the dems to win, they need to defend PA and the other four states and make inroads into either New Hampshire or North Carolina.
This will be a bit harder (D + 1.8%).

Based on the same kind of standard deviation approach I take to the presidential election, with a 4 point margin of error, 0.4% in favor of the republicans is 0.1 standard deviations. This indicates that there is a 46.0% chance of the republicans winning the senate. 1.8% in favor of the democrats is a lot harder to pull off and is 0.45 standard deviations from the latest projections. This indicates that there's a 32.6% chance of the democrats winning the senate. That being said, there's a 21.4% chance of the senate being a tie. To put this in a more readable format:

Senate chances

Republicans: 46.0%

Democrats: 32.6%

Tie: 21.4%

Once again, this assumes a probability distribution based on a 4 point margin of error, with trends being country wide. Real results may vary since if one party focuses heavily on certain races, it can tip the balance more easily.

All in all, it's anyone's race. We could reasonably see a senate controlled by either, or neither party next year. The electoral odds do favor the republicans more than the democrats though. Still, even if a tie happens, that means the vice president will break ties in the votes. Considering how Hillary is sitting at an 80%+ chance of winning, that means a tie is also a de facto win for democrats assuming a vote strictly among party lines. So while the republicans have more of a chance at outright controlling the senate, the democrats have more of a chance of de facto control, if not outright control. Still, it's anyone's game. Anything can happen at this point. This isn't the presidential race where Clinton is consistently dominating Trump. Either party can win here.