The Republican and Democratic National Conventions that precede each US presidential election have no useful purpose these days. Candidates are already chosen following a long and painfully drawn-out process of primaries and caucuses, and even more painfully drawn-out process of televised debates.

Only very very rarely is the outcome of a convention not known well in advance, even if we had the charade in 2008 of Hilary Clinton conceding to Barack Obama mid-count on the Democrat convention floor. They are really huge overblown infomercials, guaranteed airplay on television without the irritating impost of paying for advertising time.

The Republican four-day infomercial drew to a close at Tampa, Florida on Thursday, even if the first day was curtailed due to the threat of Cyclone/Hurricane Isaac. To no one's surprise, Mittens Romney won the nomination as the GOP candidate for the electoral college candidates who will, in turn, be chosen by the American people on November 6.

There was some fun along the way. The speech by Romney's vice-presidential running dog Paul Ryan was brutally fact-checked by of all people, Fox News. Senator Marco Rubio put himself forward as a contender to watch for 2016 with his speech on Wednesday night.

On the downside, a GOP attendee was ejected from the convention after reportedly throwing peanuts at an African-American CNN camerawoman and shouting "this is how we feed animals".

But we really need to give a shout to the Convention's "mystery guest" who took the stage just before Mittens was to give his acceptance speech. Clint Eastwood, at the age of 82 delivered his finest performance since the unnamed jet squadron leader in 1955's "Tarantula", conducting a dialogue with an imaginary President Obama who, apparently, was sitting invisibly on a very real chair.

That other great Republican lead actor James Stewart, and his rabbit friend "Harvey", would have been proud. Fox News, in its own inimitable fashion, said that

Legendary Hollywood tough guy Clint Eastwood brought down the house with a comic turn

Here is the video of Clint Eastwood's "comic turn"

Mind you, forty-three years before Clint was talking to furniture, he talked to the trees: