Well, its pretty clear he couldn't beat Roosevelt, he might have a chance against Taft. Even though his election is very important to history, 1893 was not really that close. Its just the textbook example of the two very different Americas of the time. Here's an idea, McKinely lives to the end of the term. We now know that Roosevelt was working a little behind the scenes against McKinely's wishes. Maybe the Democrats find this out, and make it a big issue (it sounds like the type of thing that would happen in more modern politics). Roosevelt doesn't get nominated due to the controversy. It doesn't take too much of a stretch to imagine that Bryan gets the nomination in 1904. He maybe could defeat someone other than Roosevelt.