Key Senate races — update, with prediction

Two years ago I published a bunch of diaries on Senate races, with elaborate graphs.  

They’re BAAAAACK!

Method:

 1.  I gathered polling data from Pollster.com and from brownsox‘s summaries.  I only included polls in 2008.

 2.  I assigned the undecided in two ways: 60% to the challenger (per general practice) and 50-50.  The first method is represented by solid boxes.  The latter method by hollow dots.  

 3.  I then added loess lines to all 4 series of boxes: Solid lines for the solid boxes, dotted lines for the hollow dots.  Good descriptions of loess (aka local regression) are here  (technical notes on local regression)

Some notes:

 1.   For any poll and for either method, the percentages add to 100.  

 2.  If the hollow box is far from the solid box, then there are a lot of undecideds.

pollster.com has its own charts, and there’s nothing wrong with them.  I like mine better.  First, they have more information. I show different outcomes with different divisions of the undecided.  Second, I like my smooths better.  Third, I assign the undecideds, making things a little less choppy.  

there are  races, below the fold

There are now 15 states where the Senate race is judged by 538 to not be “safe”. :

Nate Silver (aka poblano) rates these as

Safe Dem takeover: VA, NM

Likely Dem: AK, NH, NJ

Lean Dem: CO

Tilt Dem: none

Tilt Repub: none

Lean GOP: MSB, OR, MN, NC

Likely GOP: ID, TX, ME, KY, GA

Note that 14 of these (all but NJ) are currently Republican held

Since I have little interest in figuring out whether, e.g. John Kerry wins by 30 points or 40 points, I confine my analysis to these 15.

Alaska

Nothing new since last time.  This is pretty close to ‘safe’, unless somehow Stevens wins the primary (very likely), goes to trial (somewhat likely), and gets acquitted before the election (not too likely)

Colorado



Udall continues to gain on Schafer.  Also looking very good.

Georgia

poblano now lists this one as “likely GOP”:



Martin is gaining, fast.  No new polls since last time.

Idaho

Still not many polls — it doesn’t look very promising, but you never know; lots of undecided voters (note that I had to change the scale!)

Kentucky

No new polls since last time. McConnell (R) is expanding his lead over Lunsford.  This is starting to look very difficult

Louisiana (note that 538 now has this as “safe Dem”)

No new polls since last time, this is now looking safer than a few weeks ago

Maine

Also nothing new since last time.  Allen (D) has stopped making up ground against Collins (R).  Still, he isn’t losing any ground, and the lead is only about 10 points.

Minnesota

Another with no new polls. Franken (D) appears to have stopped the decline and is now making up ground against Coleman (R).  This is looking more competitive.

Mississippi

The new polls here are bad for our side…. MS was always a bit of a longshot.

New Hampshire

Shaheen (D) has a fairly steady lead over Sununu (R), and new polls confirm it.  Probably our fourth most likely pickup (after VA, NM and AK) or maybe fifth (CO)

New Jersey

This looks pretty safe, to me.

North Carolina

Hagan (D) continues gaining ground on Dole (R), and is now slightly ahead!.

Oregon

No new polls. After showing steady gains in the early part of the year, Merkley (D) has stopped gaining. But it’s close, and November is still a ways off.  

Texas

Cornyn has a considerable lead over Noriega… and nothing is changed in the newest poll

Predictions:



Gaining exactly          Chance

2                         0.04%

3                         0.71%

4                         5.14%

5                        17.88%

6                        31.02%

7                        25.95%

8                        13.90%

9                         4.24%

10                        0.92%

11                        0.19%

12                        0.01%