There have been a lot of articles in the media lately saying that 538 is overestimating Obama's chances. I don't blame them. Republicans need to keep their supporters enthusiastic. If it is a forgone conclusion that they will lose, who would want to spend their time volunteering or give money to the campaign? Those in the traditional media want an interesting story. It's in their financial interest to make this campaign seem as close as possible.
Nate Silver currently estimates the president's chances of winning at 83.7%. I'm going to make the case that this is too LOW. If I had to guess, I would put the president's chances at closer to 95% right now. Here's why:
1) Lag time
Nate Silver has admitted himself that his model is slow to react to trends. The model is mostly based on polls. Some of the polls included in averages started in the field 5 or 6 days ago. President Obama's widely praised response to Hurricane Sandy will take a while to digest. If this were a non-election week, it might take until next Wednesday to fully see the extent of Obama's bounce.
538 also smooths out short-term fluctuations. It is slow to react to poll changes when there is a reason for the fluctuations. It took over a week for the model to really show the effect of the Denver debate. I expect Obama's win percentage to continue to creep upward as we get closer to Tuesday, but right now, 83.7% is too low.
2) GOTV
Most anecdotal evidence points to a vastly superior Democratic ground game. How do you quantify this? You can count campaign offices or campaign contacts, but this is very crude and probably totally inaccurate. Consequently, the model can't take this into account. How could it?
This year has shown a very high disparity between registered voters and likely voters. It has been around 5-6% as opposed to the 1-2% that we see in normal years. It is my theory that much of this discrepancy has to do with Hillary vs. Obama in 2008. Both candidates made extraordinary efforts to register voters in all 50 states. Many of these voters in non-swing states might not bother to vote this time. However, in swing states, there will be a strong GOTV effort, I just can't imagine a 5-6% gap.
3) The MATH
Barack Obama has 4 distinct paths to victory:
Win OHIO
Win FLORIDA
Win VIRGINIA
Win COLORADO
I'm going to give the president Wisconsin. His lead there is comparable to his lead in Pennsylvania, and I just don't see him losing it. The president has fairly significant leads in all of the other swing states except North Carolina. If he wins NC, he also wins Virginia and therefore the election.
If Obama wins Florida, it's over. If he wins Ohio, he just needs one of New Hampshire, Iowa or Nevada to win. If he wins Virginia, he needs two little swing states
If he wins Colorado but loses all the other big states, he needs all 3 little states.
President Obama is a fairly strong favorite to win all 3 little states, especially Nevada
The president has a solid polling lead in Ohio, small leads in Virginia and Colorado, and is about even in Florida. The only way that he can lose is if all of the state polls are systematically wrong. Here's the problem: for Obama to lose, the state polls must be all wrong THE SAME WAY. All four states are very, very different and Obama has different strengths in each state. Ohio has the auto sector, Colorado a large Latino population and Virginia has a large government population and Florida - well, Florida is Florida. It's possible but unlikely for the state polls to be systematically wrong in one state. It is virtually impossible for the state polls to be systematically wrong in ALL four states.
Let's assume that the polls are systematically wrong in Ohio (a fairly unlikely but plausible proposition). If the polls are not systematically wrong in the other states, Obama still has about a 95% chance of winning one of the other big states and therefore an over 90% chance of winning the election.
I don't think the polls overestimate Obama's support in Ohio. Up until a couple weeks ago, The Cook Political report used to publish a characterization state races based on more accurate internal polls. In all cases, the public polls UNDERestimated Obama's support as compared to his support in public polls.
So take heart everyone. Work like crazy this weekend. GOTV. Democrats are going to win this thing. If I had a mustache, I would be willing to bet it on the election!