The predicting business can inflict heavy damage on the predictor's reputation. I think we can agree that economic forecasting during the last six months has given a brand new respectability to astrology. But still, fish have to swim, birds have to sing and columnists have to court derision and ridicule by making political predictions.

Here is the scenario I now see that, at the very least, would prove that life — to a good man, John McCain — is really unfair.

Republicans face headaches and landmines in their party gathering, while the Democrats could well write an iconic American moment.

Tradition is that the American political party not holding the White House has its nominating convention first. This year, that means that the Democrats' Denver convention beginning on Monday, Aug. 25 will be the first game of the double-header, with the Republicans scheduled to open up on Labor Day, Sept. 1, in St. Paul, Minn. (One factoid more interesting than important is that this is the first time that both parties are holding their conventions in states their presidential nominee did not carry in the previous election.)

Republican George W. Bush has, according to the venerable Gallup Poll, recently established a record low rating from the American electorate in the matter of his presidential job approval. The last time an incumbent president not running for re-election faced numbers anywhere near as bad as Bush's was Democrat Lyndon Johnson, his popularity depleted by the war in Vietnam and domestic disorder, in 1968.

That year, Johnson avoided demonstrations and embarrassment by skipping the Chicago convention, which nominated his vice president, Hubert H. Humphrey. It looks from here that John McCain in 2008 will not be as lucky as Hubert Humphrey — all signs now point to George W. Bush heading to St. Paul.

If Bush does go to the Twin Cities, he will not be there as a spectator. His position all but demands he give a prime-time speech on one of the convention's four — televised — nights. You cannot really blame Bush. Where else in America can he find a friendly crowd of several thousand, at least two out of every three of whom believe he is doing a heckuva job?

But in this campaign year when three out of four Americans want their next president to break from the policies of the Bush administration and when six out of seven of our citizens believe that "things in this country are seriously off on the wrong track, " John McCain will be busy seeking to cast himself as the Candidate of Change.

McCain does not need the most prominent visual record of his convention's opening night to be him, alone, with and standing next to or again — Heaven forbid — hugging Bush. Will there be a miraculous family emergency that intervenes that keeps Bush from Minnesota or requires McCain to fly to Arizona? Republicans can only hope and pray.

The Democrats' potential for high drama in Denver is now very much on the upside. The return of Sen. Ted Kennedy to the Senate may suggest that he, obviously ailing, could slowly come to the center stage in Denver — ideally after a Davis Guggenheim film capturing the inspiring public memories of John and Robert Kennedy. Paraphrasing his brother's words, he could say, "Now the torch has been truly passed to the leader of a new generation and a new America, the senator from Illinois ... " The emotional impact of such a moment might well register, 2,000 miles away, on the Georgetown University seismograph.

We all know that a week in politics is an eternity and that, almost literally, anything can happen. But with only six weeks to go before the Democrats gather, John McCain needs to catch a break and be spared any awkward photographic evidence that could remotely suggest a Third Bush Term.

To find out more about Mark Shields and read his past columns, visit the Creators Syndicate web page at www.creators.com.

DISTRIBUTED BY CREATORS SYNDICATE INC.

COPYRIGHT 2008 MARK SHIELDS