It’s hard to say whether Mitt Romney has been hurt by the fundraiser video and his comments on the “47%” — we won’t know until next week, when the pollsters have caught up with events. But it’s worth speculating on how these remarks could lower the ceiling on Romney’s support, and keep him from winning a majority of the electorate.

Romney’s path to victory depends on an outstanding performance among white voters. Assuming an electorate like 2008’s — 74% white, 26% nonwhite — Romney needs 61% of whites to eke out a victory in the popular vote. As Ron Brownstein points out, this would equal the best performance ever for a Republican challenger among this group of voters. In other words, not an easy mark to hit.

Romney’s best bet for reaching this target has always been working-class whites. Hit hard by the sluggish economy, these voters were the first to leave the Obama coalition — Democrats lost them by 18 points in 2008, and 30 points by 2010. Romney’s goal has always been to consolidate those voters and erode Obama’s already-tenuous support among whites as a whole. Likewise, on the other end of things, the Obama camp has been devoted to making Romney as toxic as possible to working-class whites, and blocking any gains he might make.

This is why Obama has leaned so heavily on Bain Capital, and why Romney took to hitting the administration on welfare. It’s central to the campaigns both sides are waging in Ohio and Wisconsin, and why there was some chance that Michigan would emerge as a toss-up state. In some sense, this entire election has been a contest for working-class whites, as both Obama and Romney fight to make the most out of their positions.

But the 47% remarks strike at the heart of Romney’s strategy. The 47% of Americans who don’t pay income tax are those who either don’t make enough money to qualify, or receive tax credits that offset their liability. This group includes students, the elderly, the poor and a large number of working-class families. Yes, some will not see themselves as belonging to the 47%. But when a politician disparages half the country as unwilling to “take responsibility for their lives,” at least some will see these comments as an attack on their livelihoods.

Already, Democrats are running ads that rely on Romney’s remarks. This wouldn’t be a huge problem if the controversy were restricted to the Beltway, but it isn’t. The Mother Jones video has reached more than 2.5 million viewers. Local newspapers around the country are running stories on Romney’s remarks, and local news broadcasts are also telling the story. This has become an event, and it’s one that could impact Romney’s gains among downscale whites. Even if it only marginally limits Romney’s performance, that could be enough, given his reliance on them, to prevent him from winning.

Jamelle Bouie is a staff writer at The American Prospect. You can find his blog here.