There are a number of factors that make the 2016 election unique, but the most salient dynamic is the deep and persistent unpopularity of both Trump and Clinton. According to HuffPost Pollster, 60 percent, on average, view Trump unfavorably, compared to just 35 percent who have a favorable opinion. Clinton fares only slightly better: 40 percent favorable versus 56 percent unfavorable.

And there’s a sizable pool of voters who have unfavorable opinions of both candidates that are unlikely to be swayed by the traditional pageantry of either political convention: According to Gallup, about a quarter of Americans view both Trump and Clinton unfavorably.

That likely puts a ceiling on how much momentum the candidates can generate out of the conventions as they head into August.