As Democrats prepare to formally nominate Barack Obama for President, it's a good time to remember something basic.  There is always the chance that some story outside of the  convention could blot out the campaign message.

I don't think the start of instant replay in Major League Baseball games is that story, but it certainly gives people something to talk about around the water cooler and on the news.

And I guarantee you that a certain part of the male population finds it much more interesting to chat about than the Obama Acceptance Speech, which comes the same day that MLB changes its rules.

In 1992, I was ready for a slow runup to Bill Clinton's acceptance speech at Madison Square Garden, when suddenly a bulletin showed up on the AP wire saying that Ross Perot had decided to bow out of the Presidential race.

Four years later, it was the revelation that Clinton-strategist-now-turned-Clinton-hater Dick Morris had paid a lady of the night to suck on his toes.  That sort of took some of the luster off of Bill's second Acceptance Speech.

I'm not expecting anything like that to interrupt Barack Obama, but there is that big glob of a Hurricane named Gustav rumbling towards the Gulf Of Mexico.

And certainly that has all the trappings of a dangerous storm that could basically drain away big time coverage of the Republican Convention next week.

Especially if hits, well, you know where.

Or, the way things are going, maybe the Russians are going to do something crazy, since they seem to be issuing daily threats against the US and former Soviet Eastern Bloc nations.

"We will have to react somehow, to react, of course in a military way," said Russian President Dmitry Medvedev.

The Democrats kept to their message pretty well on the first two nights of this convention and they may be on their way to four in a row.

The odds of Republicans and John McCain doing that may depend on Gustav.