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.
I’m going to work off the polls when they’re available, 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.
AL: Richard Shelby: Primaries done. Lead has grown to +32 in Rasmussen. 99.9% R victory.
AK: Lisa Murkowski (primaried): Primary count in progress. I still can’t find any polling, as Joe Miller seems to have surprised many (though not all) observers. 99% R victory (from 99.9%).
AZ: John McCain: Primaries done. McCain up 15-20 over Glassman. 99% R victory
AR: Blanche Lincoln: Primaries done. John Boozman up 20+ in polling. 99% R victory.
CA: Barbara Boxer: Primaries done. Polling mixed. 45% R victory.
CO: Michael Bennet: Primaries done. Polls shifting toward Ken Buck. 75% R victory (from 55).
CT: Chris Dodd (retiring): Primaries done. McMahon making steady gains on Blumenthal. 15% R victory.
DE: Joe Biden (resigned): Primaries in progress. Mike Castle’s lead down to the teens. 95% R victory.
FL: Mel Martinez (resigned): Primaries done. Charlie Crist appearing to get pulled from both sides to Marco Rubio’s benefit. 85% R victory (from 55).
GA: Johnny Isakson: Primaries done. Isakson lead in the 20s save for one Insider Advantage poll. If it’s confirmed by others this rating will move further. 99% R victory (from 99.9).
HI: Daniel Inouye: Primaries in progress. Inouye nearing 70 in poll. 0.1% R victory.
ID: Mike Crapo: Primaries done. Crapo lead hovering around 40. 99.9% R victory.
IL: Barack Obama (resigned): Primaries done. Illinois hates both candidates, but polling close and closing further thanks to gains by Alexi Giannoulias. 55% R victory (from 60).
IN: Evan Bayh (retiring): Primaries done. Dan Coats lead growing. 99% R victory.
IA: Chuck Grassley: Primaries done. Grassley rebounds from one bad poll. 99% R victory.
KS: Sam Brownback (retiring): Primaries done. Republican Jerry Moran leading all polls. 99.9% R victory.
KY: Jim Bunning (retiring). Primaries done. Randal Paul ahead in most polls. Jack Conway leads in one poll but I reject it. 75% R victory.
LA: David Vitter: Primaries done. Vitter holding steady in the polls. 90% R victory.
MD: Barbara Mikulski: Primaries in progress. One “bad” +16 poll not enough to knock this rating down for Mikulski. 0.1% R victory.
MO: Kit Bond (retiring): Primaries done. Apart from one questionable poll, Roy Blunt’s lead growing. 85% R victory (from 75).
NV: Harry Reid: Primaries done. Sharron Angle ties it back up. 50% R victory (from 45).
NC: Richard Burr: Primaries done. Burr keeping lead but yet unable to pull back ahead by double figures. 70% R victory.
ND: Byron Dorgan (retiring): Primaries are done. John Hoeven leads by so much he breaks the graphics in my analysis tool. 99.9% R victory.
NH: Judd Gregg (retiring): Primaries in progress. Kelly Ayotte bouncing back. 85% R victory (from 80).
NY: Chuck Schumer: Primaries in progress. Schumer’s lowest lead in any poll was 19. 0.1% R victory.
NY: Kirsten Gillibrand: Primaries in progress. Gillibrand leads every matchup. 1% R victory.
OH: George Voinovich (retiring): Primaries done. Portman takes lead over Fisher. 70% R victory
OK: Tom Coburn: Primaries done. Coburn lead approaching 40. 99.9% R victory.
OR: Ron Wyden: Primaries done. Recent polling very good to Wyden. 1% R victory (from 10).
PA: Arlen Specter (primaried): Primaries done (especially for Specter). Pat Toomey approaching double figure leads all month. 80% R victory (from 65).
SC: Jim DeMint: Primaries done. No polling I can find. 99.9% R victory.
SD: John Thune: Primaries done. Unopposed. 100% R victory.
UT: Bob Bennett (primaried): Primaries done. Lee up 30. 99.9% R victory.
VT: Patrick Leahy: Primaries in progress. Leahy up 35. 0.1% R victory.
WA: Patty Murray: Primary done. Rossi takes first polling lead. 45% R victory (from 40).
WV: Robert Byrd (died): Special election in progress. Manchin leads by 16. 1% R victory.
WI: Russ Feingold: Primaries in progress. Polling mixed and very close. 45% R victory.
100,000 trials using the probabilities above.
A 7 (from 6) seat Republican gain is most likely according to these estimates, with 6 close behind, and 8 in third. Those three outcomes account for 62% (61,660/100,000) of the curve. 4% (3,856/100,000) of the trials gave Republicans a Senate majority, about double the chance I found last time. Only 4 of 100,000 gave Democrats a gain.
So we have another slight gain from last time for Republicans, making it two in a row that have ratcheted the opposition up a seat. A majority change is still unlikely according to the polls, but GOP gains are still overtaking the setbacks.