Put it this way: Mitt Romney’s route to the White House is perilously thin. He has little margin for error. Recent polls suggest Barack Obama has benefited from the Democratic convention much more than Romney was helped by the Republican party’s gathering in Florida.
As always, it is worth recalling that polling advantages in late August or even early to mid September are rarely dispositive. Of course Romney can still win but that’s hardly the same as thinking he’s likely to.
The map at the top of this post – compiled at 270 To Win – shows how Romney could squeak an electoral college tie and send the election to the House of Representatives. That result is necessarily improbable but it’s just one illustration of how narrow Romney’s path to victory really is.
To put it simply: even if Romney wins back Indiana, Nevada, Colorado, Iowa, North Carolina and Virginia he’s still likely to need Florida to actually cross the winning-line. If he loses Florida winning Ohio and New Hampshire or, even less probably, Ohio and Wisconsin will not be enough. (Wisconsin has voted for the Democratic candidate in every election since 1988. I see little reason to suppose that it will plump for Romney-Ryan this time.)
In fact, as Nate Silver demonstrates, it is almost impossible to see how Romney can win without triumphing in Florida. By contrast, Obama has more margin for error. Silver’s definition of a “must-win” state is the correct one: “So what we might really think of as must-win states are those that a candidate could not afford to lose even in a close election.”
Viewed in these terms, North Carolina and Virginia are not quite “must-win” states for Obama but they probably are for Romney.