Who were the two candidates for president of the United States?

The two candidates for president of the United States in the story are Deutscher and Keith. When the story begins, Eckels and the man behind the desk at the time travel business discuss the recent election. Both men are greatly relieved that Keith won the election. The man behind the desk says of Deutscher:

There’s an anti-everything man for you, a militarist, anti-Christ, anti-human, anti-intellectual.

The word Deutsch means German. In the year 1952, when the story was written, the name would have conjured up images of Adolph Hitler, who had been defeated only seven years before in World War II. The story suggests that if Deutscher been democratically elected, as Hitler was, he would have, like Hitler in Germany, led the country down the path to tyranny and disaster.
When Eckels returns from his time travel adventure, Deutscher has been elected president, showing that by leaving the path, Eckels changed history in a terrible way.