If every eligible voter was allowed to vote, Obama would win no questions asked

There’s one advantage that President Obama has that Mitt Romney probably doesn’t. If he can get a good turnout from his base, he’ll be the heavy favorite to win in November — even if Mr. Romney gets a strong turnout as well.

On average over the last five public surveys, 35 percent of registered voters identify themselves as Democrats and 30 percent as Republicans. That advantage is down somewhat for Democrats since 2008, but it is an advantage nevertheless.

In the regular, likely-voter version of our “now-cast,” Mr. Obama is estimated to have a 68 percent chance of winning the Electoral College in an election held today. But on the basis of registered voters, he would be a 91 percent favorite. Instead of being ahead in the popular vote by a hair over one point, he’d be expected to win by around four. And he’d be projected to win 322 electoral votes, rather than 291.