From this blog post by Nate Silver just out: his forecast is that Ohio has roughly a 50% chance of deciding the election.
We are now running about 40,000 Electoral College simulations each day. In the simulations that we ran on Monday, the candidate who won Ohio won the election roughly 38,000 times, or in about 95 percent of the cases. (Mr. Romney won in about 1,400 simulations despite losing Ohio, while Mr. Obama did so roughly 550 times.)
Whether you call Ohio a “must-win” is a matter of semantics, but its essential role in the Electoral College should not be hard to grasp.
Were he to lose Ohio, Mr. Romney would have a number of undesirable, although not impossible, options.
More below the zest a l'orange.
I know some people have spoken out about how they resent Ohio and its role in deciding this presidential election. Some with more seriousness than others. All I can say, folks, is it ain't what other people make it out to be. We're only 11.5 million Americans in a country of about 311 million, how did we end up with this outsized role? I guess it comes down to the fact that we are a purplish state, and that we are representative of the country in terms of demographics and our economy. If you were to ask people in Cleveland about their attitudes on issues, their responses would probably resemble those if you ask the same questions in New England. If you went through the same exercise in Cincinnati, you would probably get a reflection of the same attitudes of folks in the South. Those of us here in Columbus and Central Ohio, probably a mix of responses. So we are a purple state, and the presidential candidates, the national parties, and the outside groups are fighting hard for our votes now.
Consider the U.S. Senate race between Sen. Sherrod Brown and Josh Mandel. Outside groups, the "dark money" folks, and Mandel's campaign, have spent about $23 million this cycle trying to defeat him. It will probably be the most expensive Senate race this cycle.
Back to Nate Silver's analysis of the Electoral College scenarios. I seem to recall that this probability-- that a voter will cast the deciding ballot for the Electoral College winner-- has soared for Ohio in recent weeks. In his previous projection of the "tipping point", Ohio was also first among the states, but it was not that far ahead of Nevada and Virginia. I can't find the history of this metric, if Nate keeps one, so I have only my own memory of this.
Part of this is a reflection that the race has tightened between Obama and Romney in a number of battleground states, and both sides have literally been blitzing the battlegrounds with advertisements and GOTV efforts. It now seems like the drive-time news programs (when I'm most likely to see TV advertising) are dominated by commercials for Obama, Romney, Brown, Mandel, or outside groups pushing against a candidate.
Nate seems to make the case that both Obama and Romney need to win Ohio, and also states that Obama's lead in the Electoral College and nationally is predicated on his lead in Ohio:
But if Ohio is almost a must-win for Mr. Romney, the same case could be argued for Mr. Obama. Were he to lose Ohio, Mr. Obama would then need to carry either Virginia or Colorado — along with holding Wisconsin, Iowa and Nevada.
In other words, Mr. Obama would need to carry at least one of the states where he is now tied in the forecast rather than leading. Thus, Mr. Obama’s narrow lead in Ohio accounts for the bulk of his overall advantage in the forecast right now. Were Ohio decreed to Mr. Romney by fiat, Mr. Obama’s chances of winning would decline to 57 percent from 70 percent in the forecast.
Ohio, because of its demographics and the fact that it has more electoral votes than Virginia, Wisconsin, or Nevada, has leaped into the lead in deciding this election. This explains why either Romney, Obama, Biden, or Ryan seem to pop in for an appearance here most days of the week now. What is surprising is that Obama seems to continue hold a narrow lead, despite the efforts of the GOP and the dark money groups. Sen. Brown's lead seems to be around 5 to 7 points, despite all of that money to defeat him. The GOP's choice of the execrable Josh Mandel has made their best effort all for naught.
To all Buckeye Kossacks, I say: VOTE. TODAY. If you haven't yet voted, whether you do it with early in-person voting or by absentee, vote, today. Make your voice heard. Win Ohio and the election for Barack and Sherrod.