Predicting Obama’s win

“It was invisible, as always,� Theodore H. White wrote of Election Day in 1960, more than half a century ago. “They had begun to vote in the villages of New Hampshire at midnight, as they always do, seven and a half hours before the candidate rose.�

Our ritual of choosing a president isn’t as invisible as it once was; early voting has been visible -- even noisy some of the time -- in Ohio, Florida and other states for weeks. Almost 32 million ballots have already been cast. But another 100 million or so will still come in today the old-fashioned way, from the traditional midnight polling in Dixville Notch, N.H., to the closing in Alaska (at 8 p.m., Anchorage time) exactly 24 hours later.

Here’s where the race stands as election day dawns: President Obama and Mitt Romney are roughly tied in national surveys. The difference between them is well within the polls’ margins of error; the popular vote too close to call.

ENDORSEMENTS: The Times’ recommendations for Nov. 6

But polls in the 10 or so battleground states, where the electoral college will be decided, give an advantage to Obama. In Ohio, the most important prize, polls show the president almost 3% ahead on average. Romney has the lead in Florida and North Carolina; Obama has the lead in Pennsylvania and Wisconsin.

Want a prediction? Here’s a rough one, based on the state-by-state surveys:

First, award Romney every swing state where he currently leads or is tied in the polls: Florida, North Carolina and Virginia. Now give Romney every swing state in which Obama’s lead is 2.5% or less: Iowa, Colorado and New Hampshire. But assume that Obama holds every state in which his lead is 2.8% or more: Ohio, Pennsylvania, Wisconsin and Nevada.

COMMENTARY AND ANALYSIS: Obama vs. Romney

The result? Obama wins in a squeaker, with 271 electoral votes to Romney’s 269. Even if you give Romney a 2.5% bonus above his showing in the polls, Obama still wins.

That’s why the GOP candidate has been spending time in states such as Ohio and Pennsylvania: He needs an upset victory somewhere -- an unexpected wave of votes that proves the pollsters wrong.

How certain am I of that forecast? Not very. Voters retain the ability to surprise. “It is the essence of the act,� White wrote of election day in 1960, “that as it happens it is a mystery in which millions of people each fit one fragment of a total secret together, none of them knowing the shape of the whole.�

ALSO:

McManus: The likely winner -- gridlock

Goldberg: Nate Silver’s numbers racket

Latino vote for Obama could be historic high, poll says

Follow Doyle McManus on Twitter @DoyleMcManus