How tough is it to counter-program against summer reruns, anyway? CNN’s coverage of the second Democratic presidential debate managed to improve in the second round, but viewership still fell far short of the first debate’s second round on NBC. The Hollywood Reporter gave it an optimistic spin, but millions of viewers from v1.2 took a pass:

The second half of CNN’s Democratic primary debate scored better ratings than the first, rising by double digits in the early numbers.

Wednesday’s coverage drew a combined 8.7 household rating in metered markets on CNN and CNN International, up about 19 percent from a preliminary 7.3 for Tuesday’s telecast. Each night featured 10 candidates in the crowded field of Democratic presidential hopefuls.

Tuesday’s debate ended up with 8.69 million viewers. Should the gains in Wednesday’s early ratings carry through to the finals, CNN will likely end up with about 10 million viewers (more complete figures will be available later in the day).

Just how impressive was the one-night gain, though? Despite attempting to distribute the candidates more equally the second time around, the DNC ended up with a similar problem as the first debate. The Joe Biden-Kamala Harris grudge match was the big draw, followed by the Biden-Cory Booker match. Since Biden is by far the most popular candidate in the 20-plus field, it stands to reason that more people would tune in to see him take on nine of the other candidates no matter how the DNC matched him up anyway. A double-digit gain would have been predictable; it would have been a bigger story had it not occurred.

Even with the gain, though, last night’s ratings fell far short of either night from the first debate. To remind everyone, the NBC debate drew 15.3 million viewers for the first round and 18.1 million for the second round. CNN’s debate barely beat NBC’s round two put together. If the numbers hold up, Democrats will have lost around 40% of their Round Two audience over the course of a month.

The numbers themselves aren’t bad on their own, but such a sharp decline in interest should worry the DNC. So what’s the problem? Jim Geraghty thinks it might be the format:

There are no good formats for ten-candidate debates, only less bad ones. If you want to have a better quality of debate, the DNC has to tell more candidates something they will hate hearing: “You’re just not popular or important enough to participate in our prime-time debates.”

Yes, 60 seconds is an extremely short period of time to explain any policy, decision, or idea. But the short time limits are there because otherwise the last candidate to get a question won’t speak for the first half-hour or so. In the first debate on MSNBC, Marianne Williamson didn’t speak for the first 30 minutes. Even with a seemingly reasonable two-minute limit, if the moderators try to spread around the question evenly, about twenty to twenty-five minutes will pass in between answers from any individual candidate. (Nine candidates, two minutes each for answers, plus time for questions and applause. And this is separate from commercial breaks!)

Pick your poison: short time limits for answers, or having candidates standing around waiting for nearly a half hour to say anything.

On the other hand, it might also be the content. The sharp-leftward lurch by most of the candidates on stage from the previous Democratic status quo could be turning off viewers. Or it could be a combination of both, since this format incentivizes shock over substance that results in nothing more than the same old campaign sound bites that viewers can hear from the candidates nearly anywhere else.

Whatever the problem is with viewer interest, the DNC had better figure it out fast before it translates into voter disinterest. The numbers aren’t terrible at the moment by any stretch, but the trend certainly looks worrisome … although, as Harvey writes at IMAO, it could be worse.