Will Barack join the Mile High club? Rumours are still buzzing about the possibility that Mr Change will give his acceptance speech in the 73,000 seat Invesco “Mile High” stadium, rather than the Pepsi Convention Centre where the conference is being held.

The talk is formally of the speech by “the nominee” being moved there, but obviously, had it been Hillary or John Edwards, no-one would be rushing to book one of the largest stadiums in the mid-West. But with Obama, there is virtually no danger of the event being a fizzer, or of empty seats. If you book him, they will come.

Democratic strategists would be hoping that the grand slam of a mass rally, with Obama at his prophetic best, will ramp the campaign up to a new level, one that Republicans cannot possibly match. The Republican Convention starts days after the Democratic one concludes, a manoeuvre that usually gives the advantage of speaking second.

This year, however, the GOP is heading into a nightmare — a candidate whose talents are not best suited to major public speaking, following the greatest orator of the last quarter-century. McCain’s characteristic speaking style — throwing out jokes to key reporters on his plane, while slurping from a grande latte — ain’t going to fly.

Nor are the broader visuals looking good for the right. The DNC will be a mass, carnivalesque event with a lot of youth and energy, while the GOP event is going to look like a Regional Plumbing Supplies Sales Conference in the Akron Ramada. Nor would they gain much advantage by sticking young people in front of the camera — I mean have you seen Young Republicans? One look at these blue-suited zombies and blondorexic stepfords and Idaho would be an Obama-Nader head-to-head.

Should current conditions hold, and in the absence of major scandals, attacks, etc, the Democrats hope that the current 5-7% lead will serve as a platform to reach towards a 9-10% lead, which would be sufficient to deliver states such as Georgia and Montana, and to bring a range of hitherto unthinkable states — Alaska, South Carolina, the Dakotas — out of the uncontestable category and into play for 2012.

Conversely, should something go horribly wrong in the next six weeks, the Convention and the speech will serve as a rallying point to regroup and redirect energies.

By contrast the McCain campaign appears to have no shape, no arc. Where Obama’s switch to the centre on a range of issues was rapid and decisive, McCain — both the campaign and the man himself — seem devoid of energy.

That may be a strategy in itself of course — running slow and cautious and hoping that Obama will come to seem untethered and unreliable — but it’s also possible that the candidate will never find the puff he needs to start setting an agenda. The campaign had its first reshuffle last week, with manager Rick Davis moved sideways to make room for former Schwarzenegger advisor Steve Schmidt.

That may yield results, but the problems for the McCain camp go deeper. It is difficult to think of a worse statement than “I don’t know much about economics, I’m running on national security grounds” hanging round your neck in this election. McCain, for reasons best known to himself, has thrown off variations on this statement at least three times, and then compounded the problem by denying he ever said it.

The statement is very much in the McCain style — an interest in being an imperial leader, facing the world, rather than being concerned with the boring domestic concerns of the interior. Gambling on a continued public concern about the war on terror, McCain has found that the issues has just about disappeared — to the point where even talking terrorist attacks on US soil starts to sound, as did McCain’s hapless advisor Charlie Black, like wishful thinking.

Indeed, the current decline of violence in Iraq may well have been worse for McCain than continued fighting there. Were al-Qaeda, or anyone who could be called al-Qaeda, still slugging it out, McCain would have a plausible “transcendental threat” to focus on. As it is, his strategic argument has been borne out by the surge (for now) — but gratitude is the least potable of political benefits, and a calmer Iraq has simply created a vacuum into which domestic worries — which Obama or any Democrat is best-placed to address — can play.