McCain would be a popular choice.
From CBS News | Dan Rather's Convention Journal | August 29, 2004?09:32:44:
"Not much of it, really. Only a few people besides workmen inside the hall. Among the few who were there, the most popular topic of conversation was whether President Bush might surprise and announce during the convention that Vice President Cheney would not be running with him this year.
This rumor has swirled around a bit from time to time throughout the year, the chatter being that Mr. Bush would prefer to run with Sen. John McCain "