On Wednesday and Thursday nights, as the first two Democratic debates wind down around 11 p.m. Eastern, viewers seeking postgame reaction can watch supersize panels on cable news or scroll through Twitter.

Or they can tune into the late-night shows.

Back in the old days — that would be four years ago — the presidential primary debates were of so little concern to late-night hosts that they happily taped their episodes hours in advance. They only addressed candidates sparring on a stage some 25 hours later.

Not anymore.

For the first time, “The Tonight Show” will go live in its entirety after a major political event. “The Daily Show” will go live for two consecutive nights for the first time. And in what is believed to be a first, two 11:30 p.m. network late shows — Jimmy Fallon’s on NBC and Stephen Colbert’s on CBS — will go head-to-head live for a full hour. Seth Meyers’s hourlong 12:30 a.m. show will also be live both nights, allowing on-air jokes and jabs to continue into the wee hours.