Supposedly, McKinley's own choice to be his running mate in 1900 was Senator Charles Fairbanks of Indiana. (It's not clear, though, that Fairbanks would have accepted--in OTL he reportedly turned down overtures from Hanna, believing that the Senate was a better route to the presidential nomination in 1904.) Assuming that Fairbanks accepts and that McKinley's assassination is not butterflied away, we get a considerably more conservative president than TR. In fact, *all* the potential McKinley running mates in 1900 (if TR was not around) look more conservative than TR--if for example, he wanted to balance the ticket with an easterner (as in 1896) possible candidates would be Elihu Root or Henry Cabot Lodge.