Notes on the expanded three-way simulator

In simulating elections, we've so far been able to mostly ignore third-party candidates in determining the chances of victory--they've been so far behind that there isn't any need to calculate their probability of victory because it's essentially zero. In R code (the language under which our simulations are run) the relevant section of the simulator looks like this:

for(i in 1:100000) {
...
        if(D > R) {
              result <- 1 ## Democrat wins
        } else {
              result <- 0 ## Republican wins
        }

        cumulative <- cumulative + result
    }
    cumulative / 1000 ## Democratic win percentage

Close-Up: Independent Candidates in Sparsely Populated Prairie States Are Ruining Our Probabilities

Polls in the Great Plains delivered another defiant middle finger to our conventional wisdom about the Senate races this year. SurveyUSA released its latest survey of the state, and while Democratic no-name Rick Weiland remains at his sub-30% support, the major change is that this poll is the first one to put independent and former Republican Sen. Larry Pressler in a clear second place behind former Gov. Mike Rounds.

There's a bit of a paradox here, though. When we talk about third party candidates we inevitably wonder: is the candidate spoiling votes for the Democrat or the Republican? In South Dakota, before ever looking at the polls, we would guess that Pressler was spoiling votes for Rounds, the Republican, since Pressler represented South Dakota in the Senate as a Republican for 18 years before losing the seat to the man who currently holds it, retiring Sen. Tim Johnson. The trends seem to confirm this--Pressler's support has generally grown since the summer, while Rounds still remains ahead but seems to have trouble breaking the low 40s in the polls compared to the summer, where his best performance was 59% in the first iteration of the YouGov panel survey. (Note, however, that that survey did not include Pressler as an option.)

Larry Pressler, then (1979) and now (2013).

Ratings Update: September 30, 2014

Long story short, some new fundraising data came in, which was really helpful to our model for splitting undecided voters. As a result, Democrats' chances ticked up in two gubernatorial races and ticked down in two others, with no change in the Senate, where Democrats have a 42% chance of retaining the chamber. Not a pure toss-up like it was a week ago, but if you've got a gun to your head you really don't want to bank on that. 

And here are the gubernatorial races:

Partisan polls, new developments, and the Kansas that happened before Kansas

On September 3 the Democratic district attorney from Shawnee County, Kansas, Chad Taylor, officially announced his withdrawal from the election for U.S. Senate. This caused quite a stir among political observers, who then had to contend with the possibility of a unified challenge to incumbent Sen. Pat Roberts by independent Greg Orman. Drama ensued as Secretary of State Kris Kobach refused to remove Taylor's name from the ballot and there was a legal battle over it and now the Democrats are--kinda?--still on the ballot, but without Taylor's name next to the D. The Kansas Supreme Court hasn't made quite clear whether the Kansas Democratic Party has to nominate a replacement candidate.

It's that Senate race that's received a lot of attention in the last three weeks, but what's been neglected is that Alaska Democrats beat Kansas Democrats to the punch by one day. Gov. Sean Parnell was supposed to be a lock for re-election: after ascending to the office following Gov. Sarah Palin's resignation in 2009, Parnell was first elected to the position in 2010 by a margin of over 20 points, with the largest ever share of the vote for any Alaska gubernatorial candidate in history (59%). No one in the spring and even right up until the primary on August 19 questioned what seemed to be a fact of Alaskan political life. 

Of course, it's because no one counted on two earth-shakers.

Kansas and incumbency advantages in our model

I said last time that we have no clue what's going on in Kansas, and it just got harder to tell, since yesterday the Kansas Supreme Court ruled that Democrat Chad Taylor could have his name removed from the ballot. With Taylor presumably out of the picture (to be replaced by "random Democrat", if Secretary of State Kris Kobach's next order stands), the only polls that make sense now are the ones that ask about a matchup between independent Greg Orman and Republican Sen. Pat Roberts.

 

Unfortunately, that doesn't make matters any simpler. To begin with, very few polls asked about what would happen if it were just Orman vs. Roberts; in fact, the YouGov / New York Times / CBS poll didn't even include Orman in their question, as it was conducted when Taylor was still in the race. 

NEW: A table and a cool graph

From now on I'll be regularly updating a histogram and a table for the current Senate forecast. It's got some real nice red, white, and blue colors in it, and there's a link to it here. But it'll always be viewable from the little navbar at the top; just click "The Senate Outlook for November 4" and it'll bring you to the right tab.

For your convenience, though, here's what it's looking like:

Ratings Update: September 19, 2014

We're less than seven weeks out from the elections, and it's around now that some uncertainty begins dropping out of the forecast--mainly because 1) there's more polling out, giving us a more accurate picture of where candidates stand, and 2) there's less time for the underdogs to make up the difference before the election. So a lot of our ratings changes this time will be adjusting for that.