He came, he lingered awhile, then he left. I know he was here because I had a glimpse of him in Horseguards Parade with Gordon Brown, and saying a few words outside Number 10.

Oh, and he had a photo-op with David Cameron — the next Prime Minister — beside Big Ben (right), when Cameron presented him with a CD by The Smiths, apparently called “The Queen is Dead” — a very strange choice for a Tory leader.

But it was that kind of visit. Barack Obama was at pains not to look like a President-in-waiting to the folks back home, while presenting himself as just that to the foreign dignitaries he met. A weird psychological balancing act by any standards.

So how did he do?

About as well as he could have done in the circumstances. A black man as a potential President is a new experience for everyone. We all assessed him in our own way. I was struck by how unlike other black American politicians he is. Martin Luther King and Jesse Jackson both had that Alabama feel about them. A bit downtrodden, slightly angry, and from the other side of the tracks.

Obama is not like that at all. He comes across as an urbane, Harvard-educated, East-Coast liberal. There’s an elegance and poise about him that suggests he’s comfortable in his own skin, and not a trace of resentment against anyone. He reminded me of a typical English gentleman — without the accent.

I’m not too taken with his platform speaking style, though. It begins to grate a little after a while. His delivery is in short bursts of well-prepared sound-bites with a falling cadence at the end of many sentences and phrases. The predictability of this creates a mannerism which detracts from his meaning.

I much preferred Hillary Clinton’s style, particularly in the final speech of her campaign which, if you removed the over-done feminism and the achingly-Left liberalism, was of true Presidential calibre.

The final impression I had was that only Obama’s politics stand in his way now. If his voting record in the Senate is anything to go by, he may be just beyond the pale of electability to most Americans.

It’s certainly all to play for. McCain is a solid, if unexciting, candidate. It will take a real touch of class from Obama to beat him.