McCain stepped out of a sport-utility vehicle Tuesday morning with wife Cindy as a small crowd cheered "Go, John, go!" and "We love you!" One person carried a sign that read, "Use your brain, vote McCain!"
They walked into the church, cast their ballots and left within minutes, avoiding any lines.
McCain signed a poster and gave the thumbs-up sign before leaving without speaking to reporters.
Earlier, McCain could be seen on the patio of his high-rise condo, pacing with a cell phone and a large cup of coffee.