What if President William McKinley had never been assassinated?

[LabourJersey]

According to several books, Roosevelt may not have even got the nomination in 1904, regardless of his popularity. Mark Hanna's New York allies wanted to make TR Vice President mostly to get him out of Albany; I doubt Hanna and his cronies, if they were still in the White House, would have let a true Reformer like TR get the nomination at the Convention.