Nowhere were the two tracks of the primary more stark than over the weekend, when Biden positioned himself in Ohio, far from the horde of other Democratic contenders. While more than half the field jostled at the Californian Democratic Party convention here — the largest single state party gathering in the nation — the former vice president had the lectern to himself at a Human Rights Campaign dinner on Saturday, contrasting his candidacy not with any Democrat, but with the Republican president.

His counter-programming appearance served the latest reminder that, with large leads in national and several early state polls, Biden is running a race in a vacuum, adhering to his own rules and schedule. The biggest threats to his campaign at the moment aren’t his rivals so much as his advanced age and ability to remain disciplined in an era where missteps are under heightened scrutiny.

The other Democratic primary, consuming everyone else, is to see who can pull within striking distance and emerge as one of the handful of contenders still standing after the four early states vote next February.