Film Studies: Let me show you the glittering career you threw away, Orson

But to feel this speculation to the full, you have to believe that Ambersons was a great film in the making. The reasons for that thinking are the "ruined" film itself (still extraordinary), the complete script and stills of what is gone. No one can be sure that Welles back in Los Angeles could have saved his film. But he was intimidating in person, because he had a triple attack: lubricating eloquence; immense, coherent reason; and the most dreadful temper anyone had seen. He did not like to be crossed - he had little experience of it; but he had a habit of getting his own way. The guard was changing at RKO: Welles loyalist George Schaefer was giving way to Charles Koerner. Studio people were out to get Orson, and the first contract had been amended so that he did not have all the liberties on Ambersons that had applied to Kane. But Orson was truly brilliant. He could have heard the criticism of his film as slow, dark and gloomy and found ways to add pace and a bit more humour without sacrificing anything vital. It is a part of any great artist to hear shrewd, justified criticism and benefit from it. And while Welles was vain, on Kane he had regularly heeded people who knew more than he did - people such as cameraman Gregg Toland.

So I am supposing that a version of Ambersons would have been released - 120 minutes, say - to wretched business and tremendous reviews (the latter gently encouraged by Orson's own amusing stories of studio interference). He would have had two masterpieces to his name and, just by being back in the US, he would have been in a position to argue against going any further with the Rio venture (a film to promote relations between the US and South America). It had such problems already; it never amounted to a finished picture. And anyway, Orson might have said as a clinching aside, "Mr Roosevelt has asked me to stay."

And here we come to the most fascinating part of Callow's second volume - the way in which Welles devoted himself to a kind of political career as the war went on. He was not often single-minded: he did marry Rita Hayworth in 1943 and they had a daughter in 1944. But in those years, broadcasting on CBS, Welles shifted from the role of entertainer to that of political commentator and activist. He identified himself with the defendants in the Sleepy Lagoon murder case in LA, a case of racially motivated injustice. He wrote for a magazine, Free World, and he went on a lecture tour speaking against fascism. The Orson Welles Almanac on CBS became a political show and, in the 1944 election, Orson worked for FDR, despite the way in which Roosevelt had dropped Orson's political idol, vice-president Henry Wallace, from the ticket in favour of Harry Truman. He even indicated that he was not thinking of making movies any more.

When Roosevelt was elected for the fourth time, in November 1944, Orson was still only 29. Because he had been around a while, it was easy to overlook the prodigy in his career. By late '44, Orson Welles was one of the best known Americans: he had led the Mercury Theatre; he had shocked the nation with The War of the Worlds; he had made Citizen Kane; he had married Rita Hayworth; and - in our scenario - he had made The Magnificent Ambersons, which showed that the boy wonder of Kane, the trickster, the technician, could compromise with an ordinary, family story about America and Americans that stirred the nation.

When FDR died, in the spring of 1945, Orson wrote a great farewell for radio, and he could easily let it seem as if he had been very close to the dead president. There was certainly something in his early life that had the effect of a staircase: every year or so, Orson moved up and took on new challenges. He had conquered the theatre, radio and the movies. He had acquired a public voice - and it was one of the great radio voices of all time. He was handsome, funny, charming, smart - and he was all those things to excess so that there was an unquestioned feeling, in show business at least, that you couldn't trust Orson as far as you might throw him. He was divorced once already (and the Rita union would not last). He was egotistical, violent when angered and, as some saw it, fatally self-destructive. And in reality he didn't give up Rio to save Ambersons.

But it was a close call in the mid-Forties. Welles was from Wisconsin (long ago). In the post-war years, if he had tried for the Senate, he would have found himself running against Joseph McCarthy, a war veteran, a drunk, a tough guy and another pretty good speaker. A McCarthy might easily have pointed to Orson's Communist associates, his black friends, his marriages and affairs. He might have been able to point to Orson Welles as just an actor, and therefore unstable, dangerous, un-American. (Ronald Reagan was only four years older than Orson; in 1943-44, they were both Hollywood Democrats.)

You can say that Welles could never have made it. But in 1943-44 Ronald Reagan was a less likely candidate. Welles had made a film about a man who would try for president, a man whose weaknesses betrayed him. As if America has learnt not to elect fallible people. You have to wonder if America could have survived so brilliant a man as leader.

d.thomson@independent.co.uk