Monday's CNN/YouTube Democratic debate was popular with viewers age 18-34, but the format didn't sit well with everyone -- specifically, Republican presidential candidates.

The Washington Post reports this morning that so far, only Sen. John McCain, R-Ariz., and Rep. Ron Paul, R-Texas, have agreed to appear at the next CNN/YouTube debate scheduled for Sept. 17 in St. Petersburg, Fla. Mitt Romney told the Manchester Union Leader on Wednesday, "I think the presidency ought to be held at a higher level than having to answer questions from a snowman."

Romney isn't the only Republican turning up his nose at the event. According to the St. Petersburg Times, Rudy Giuliani has "scheduling issues."

So far, reports the Post, 400 questions have been uploaded to YouTube in anticipation of the debate.