The Democratic National Convention — read, panicky aides to President Obama — have decided to move his speech indoors tomorrow, from the 74,000-seat Bank of America Stadium to a 20,000-seat venue, the Time Warner Cable Center.

The Democrats are saying it is the 30 percent chance of rain that forced the change, but I imagine that not a single reporter is buying that. There is good reason for such skepticism. It is not like Obama hasn’t held rallies in the rain. And, as the Romney team eagerly points out, the weather forecast for Charlotte is improving.

So the president can’t fill a 74,000-seat stadium. That’s not surprising, considering the crowd problems his campaign has had during this election, including a tepid turnout for its very first event in May. The campaign has even gone so far as to tell reporters that it is intentionally keeping crowd size down. Ummm. Interesting tactic.

The real issues are, when did campaign aides figure this out, and why did they continue in the delusion that a huge crowd would materialize? Reports suggest that aides were trying to “cobble” together a crowd, but it seems not even offering to bus in college kids was going to do it.

The symbolism is rotten. The theme of Obama not living up to expectations (even his own!) is not one the campaign wants the media chattering about. But what the incident really tells us is that the candidate and his hacks think they’ve got their 2008 magic, when they don’t. No, merely showing up is not going to bring the base out in huge numbers. Been there. Done that.

The notion that Obama can win a base election by running to the left, painting Mitt Romney as an evil person and radical right-winger and attempting to stitch together core interest groups, is based on the assumption that the Democratic base will turn out to carry Obama home. But in 2004, an election year the Obama team likes to invoke, George W. Bush ran strongly with independents.

One canceled venue doesn’t tell us a whole lot, but it should tell the Obama team something: Its guy is not the draw he was in 2008.