The Romney evolution
There is a frequent, cheesy scene from many a science fiction film that came to my mind after the final presidential debate.
Scientists' attempts to build a life-like robot seem doomed - it is clumsy, clunky, an unconvincing failure. But then, in a time-lapse sequence, it starts looking half-way competent, then impressive, and finally performing much better than a human.
I am not, of course, saying Republican presidential nominee Mitt Romney is robotic.
But in the months I have been watching him closely, it is startling the way he has changed and improved from an improbably incompetent candidate to a much steadier, more impressive figure.
It is survival of the fittest ideas and tactics. His campaign has evolved ruthlessly.
Policies that do not appeal to the audience of the moment are cast aside. Strategies are shed as the environment changes.
The Obama campaign had, during the primary campaign, successfully portrayed him as rich and out of touch. His own performances on the stump reinforced that image.
The debates allowed him to present himself to the American people, and people liked what they saw more than what they had been told about him.
In the final debate, this evolution led to a curious role reversal.
Mr Romney cleaved close to many of President Barack Obama's policies on foreign affairs and projected himself as calm and moderate.
The president tried to tear him down, jabbing and mocking, less aggressive than the last debate, but still effective.
Now it is the president who is changing his tactics.
Derided by the press and his opponent as having no positive agenda for a second term. Here is a 20-page glossy colour pamphlet, looking suspiciously like a manifesto.
Having stopped attacking Mr Romney as a flip-flopper (because, apparently, former President Bill Clinton told the campaign that people quite like flip-floppers as pragmatic problem-solvers) he is now back to that approach, with a new name.
He mocks Mr Romney's move to the middle as a made-up malady, "Romnesia".
"If you say that you love American cars during a debate, but you wrote an article titled Let Detroit Go Bankrupt, you might have Romnesia," he told a rally on Tuesday.
The audience chanted back: "Romnesia! Romnesia!"
With the opinion polls so tight, it is the challenger who wants to appear cool and presidential and the incumbent who wants to warn that a future without him would be a frightening place.