ST. PAUL, Minn. -- The first clue that the convention hall isn't quite full is the air conditioning: walking into the Xcel Energy Center is like walking into, well, an Alaskan winter.

As you may have noticed on TV, there are empty seats all over the arena. The section directly to the right of the stage is nearly completely devoid of people. The club-level seats are practically deserted. The upper deck has plenty of room. (The sky suites seem pretty crowded, at least from the lower bowl.)

Part of the problem with the Twin Cities as a convention site is that while the business takes place here in St. Paul, most of the hotels -- and nearly all the nightly parties after the sessions adjourn -- are in Minneapolis, about 30 minutes up the road. There may be quite a few Republicans staying in, watching the convention on TV (or not) and then heading out to socialize afterwards without bothering to drop in for the show. There are short lines at the security checkpoints, no crowds in the restrooms, clear paths through the concourse between speeches.

Compare that to Denver last week, where the fire marshall closed the Pepsi Center and Mile High Stadium nearly every night, and you get a sense of that enthusiasm gap the press is talking about.

On the other hand, the Republicans have about half as many delegates as the Democrats -- while only 2,380 people are casting votes here, that would only barely win a candidate a majority of the 4,126 delegates in Denver.

The real test may come Wednesday night, when vice presidential nominee Sarah Palin headlines a speakers' roster including Cindy McCain. If a crowd doesn't turn up then, you might see half-price hot dogs for sale by Thursday, when John McCain shows up to accept his party's nomination.