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. That is, if Romney loses North Carolina (I think he'll probably win it but only just) he's more than likely to lose Virginia too. And if that happens then he's probably going to be in trouble in Florida as well.
This is not likely to be a landslide election. Bear in mind, however, that a 54-46 split pretty much counts as a landslide these days. Romney's strategy is not that adventurous. 51% will do fine, thank you very much.
But to get to 51% he needs to clobber Obama amongst white voters. At the moment - albeit with the Democratic convention still a live memory - that isn't happening. As Jonathan Chait explains:
Both campaigns seem to be assuming an electorate that is about as diverse as the one four years ago — non-white voters will probably be a little less jazzed to vote, but more of them will be eligible. That assumption, combined with Obama’s steady share of the non-white vote, produces a break-even point of around 60 percent of the white vote, or perhaps a little higher, for Romney. In the [Washington] Post’s likely voter sample, he only leads by 55 to 42 percent among white voters. That thirteen-point lead is nowhere close to the twenty-point-plus margin he probably needs.
If Obama can carry 42% of the white vote it is hard to see how he loses the election. Of course, if black and latino voters make up a smaller share of the electorate than they did four years ago then Obama's position begins to look pretty bleak.
Nevertheless, there's no doubt which campaign you'd rather run and it's not Mitt Romney's. His best chance of running from the front may have already passed. Ross Douthat:
What the Obama bounce has done, though, is dramatically reduce the possibility that this election will turn out like 1980 or 1992, when the electorate broke hard against the incumbent in the last few months of the campaign. The convention period was Mitt Romney’s best chance to pull substantially ahead of the president and set himself up to pull away. If Romney wins, it will probably be by a whisker, not a lap.
That seems right to me and, as Ross expands upon, it has always struck me as crazy that so many conservatives think Romney should be running away with this election. The GOP's path to victory has always needed a fortuitous run with the dice and while we can't rule out such a streak it's not too sensible to count on it happening either.
Play around with the electoral map yourself and you start to see how daunting - though not impossible - Romney's task really is. That doesn't mean he can't win only that if both campaigns are in some trouble one is in rather more trouble than the other.