He's such a big name here being a long time senator, I don't see him losing. It'll be contested more, unlike years past, but in the end won't matter. He'll have to have everything for him go wrong and everything else go right for whoever he ends up against for there to be a chance.
Richard Lugar was about as big a name in Indiana politics as there ever was. He lost (if in the primary instead of the general election).
Attempting to delay the vote for the vacant seat on the Supreme Court until the Trump Administration is in charge is a high-risk move in a state that leans D. He could go from 53% approval to 40% approval on that alone.