The Republicans had a presidential debate last night in South Carolina. This was their one chance to get on TV — okay, Fox News — before they slip into the obscurity that embraces the also-rans.

While candidates in presidential debates often need no introduction, the participants who filed onto the stage at the Peace Center for the Performing Arts offered an exception to that rule. There were two former governors, a member of Congress, a former senator and the former chief executive of a chain of pizza restaurants — all of whom round out the lower rung of an unsettled Republican field.

The chairman of the Republican National Committee, Reince Priebus, sought to allay the worries of party activists who believe Republicans are missing an opportunity to start defining Mr. Obama in their quest to win back the White House.

“As we all know, there are numerous other candidates that are looking at it — and thank God,” Mr. Priebus said before the proceedings began. “Quite frankly, I think Americans are sick and tired of two-year, knock-out drag-out contests with a zillion debates and forums.”

For the record, the participants were Tim Pawlenty, Rick Santorum, Gary Johnson, Ron Paul, and Herman Cain.

The highlight of the evening came when Ron Paul asked the audience if they were in favor of legalizing heroin, and they burst into applause. Maybe that’s because after watching the debate, they all needed a pain-killer.