Senate Projection for September 20

With the House update done, it’s time to move on to the new Senate update. Last week the pace of Republican gains were halted entirely as the party gave back the half seat it gained the week before. The chance of a Republican majority also dropped back to 4%. With the events of the last week I expect that to go down even further, but let’s see how much it sends up to be.

Situation

Senate right now: 59 D-41 R.

Seats up right now: 19 D-18 R.

Seats therefore not up: 40 D-23 R.

Minimum result needed for majority: -9 for Democrats, +10 for Republicans.

Method

I’m going to work off the polls when they’re available, working from Real Clear Politics, giving double weight now to Likely Voter polls, and make guesses otherwise. That’s usually easy because the seats that aren’t polled are typically safe. Changes from last time will be in boldface.

Seats

AL: Richard Shelby: Lead has grown to +32 in Rasmussen. 99.9% R victory.

AK: Lisa Murkowski (primaried): Joe Miller leads the early polling but not quite overwhelmingly. 80% R victory.

AZ: John McCain: Newest polling not low enough to drop the rating. 99% R victory

AR: Blanche Lincoln: John Boozman up 20+ in polling. 99.9% R victory.

CA: Barbara Boxer: PPP breaks the trend of LV polls favoring Fiorina. 40% R victory (from 50%).

CO: Michael Bennet: Polling volatile. 60% R victory.

CT: Chris Dodd (retiring): Blumenthal stabilized for now against McMahon gains. 15% R victory (from 10%).

DE: Joe Biden (resigned): O’Donnell win makes this a new race with a new starting point. O’Donnell depressed in mid-primary polling as well. 5% R victory (from 50%).

FL: Mel Martinez (resigned): The wrong Democrat won for Charlie Crist. 85% R victory.

GA: Johnny Isakson: Isakson rebounds in polling from one scare. 99% R victory.

HI: Daniel Inouye: Inouye nearing 70 in poll. 0.1% R victory.

ID: Mike Crapo: Crapo lead hovering around 40. 99.9% R victory.

IL: Barack Obama (resigned): Kirk edges ahead again. 55% R victory.

IN: Evan Bayh (retiring): Dan Coats lead growing. 99% R victory.

IA: Chuck Grassley: Grassley rebounds from one bad poll. 99% R victory.

KS: Sam Brownback (retiring): Republican Jerry Moran showing leads in the 40s. 99.9% R victory.

KY: Jim Bunning (retiring). Randal Paul’s lead seems to be growing, but two good polls outweighed by the CNN/Time tie. 85% R victory.

LA: David Vitter: Vitter gets a bounce in Rasmussen. 95% R victory.

MD: Barbara Mikulski: Mikulski’s primary opponent’s internal even has her ahead. 0.1% R victory.

MO: Kit Bond (retiring): Blunt marching on from one bad poll I didn’t trust anyway. 85% R victory.

NV: Harry Reid: Angle breaks the run for Reid of poll leads. 45% R victory (from 35%).

NC: Richard Burr: Burr continues good run with SurveyUSA blowout. 90% R victory (from 85%).

ND: Byron Dorgan (retiring): John Hoeven leads by so much he breaks the graphics in my analysis tool. 99.9% R victory.

NH: Judd Gregg (retiring): Kelly Ayotte wins the primary but Paul Hodes makes post-primary gains on her, negating the boost in rating Republicans would get from Ayotte’s win. 80% R victory.

NY: Chuck Schumer: Schumer hovering around 60. 0.1% R victory.

NY: Kirsten Gillibrand: Gillibrand notching leads around 20. 0.1% R victory (from 1%).

OH: George Voinovich (retiring): Portman threatening to put race away. 90% R victory (from 85%).

OK: Tom Coburn: Coburn lead approaching 40. 99.9% R victory.

OR: Ron Wyden: Recent polling very good to Wyden. My thoughts of this being a sleeper GOP victory seem to have been premature. 1% R victory.

PA: Arlen Specter (primaried): Primaries done (especially for Specter). Pat Toomey finally hits double figures in one poll. 85% R victory.

SC: Jim DeMint: No polling I can find. Alvin Greene’s indictment seems to have diminished interest in this race. 99.9% R victory.

SD: John Thune: Unopposed. 100% R victory.

UT: Bob Bennett (primaried): Deseret News confirms Rasmussen polling. 99.9% R victory.

VT: Patrick Leahy: Leahy lead down to 30. 0.1% R victory.

WA: Patty Murray: Murray has good week in polling. 30% R victory (from 60%).

WV: Robert Byrd (died): More polling to come in this race tomorrow, but too late for this week’s projection. 20% R victory (from 30%).

WI: Russ Feingold: More polling to come this week on this race as well, though primary win seems to boost Ron Johnson. 50% R victory (from 45%).

The simulation

100,000 trials using the probabilities above.

Results

Not a good week for the Republicans, not one bit. 6 (from 7) becomes the most likely Republican gain. +7 and +5 are about equally likely in second and third place, and those three outcomes account for 62% (62,451/100,000) of the curve. 1% (1,351/100,000) of the trials gave Republicans a Senate majority, down from last week’s 4% and way down from the high of 6%. Only 18 of 100,000 trials gave Democrats a gain. So oddly the Republicans seem to be keeping their floor of gains despite losing some of their ceiling possibilities for now.

Washington and Delaware this week hurt Republicans, no doubt about it, even as Nevada and Wisconsin showed small upticks. 51 votes just seem out of reach for Republicans unless some races change soon.