No way. He needs to continue to put the pressure on. You lose when you protect leads. Nothing says a loss more than knowing your ahead and changing from what got you there to something else. Many a win was prevented by using the “prevent” defense in a game.
When you pressure your opponent, they make mistakes. It may not happen every time, but the advantage of being up is that each mistake by the opponent is magnified. Set back and now the need two good things to go their way to get them back to where they were.
I say debate him. Make him make a fool of himself aT each one. Say to him, “Are you kidding me when you said delay the election?” After his response say, “You know that you can’t do that. Is set in stone and it take a a Congress to make that happen. You think Mitch, the guy who said if your running for a Senate seat that if they need to distance from you, they should, is going to help you change the date of the election? You truly are the puppet.” Then follow up with, “If I am elected, I will push to make mail-in voting standard a cross the country. I will also rebuild their postal service and not dismantle it.” Watch tRump go crazy with that, and say that stuff he said today that everyone knows this, its logic. Winner, winner, chicken dinner!
He needs to continue to show the contrast. tRump gets so much “free” media attention that you have to constantly show the contrast. The debates are a great way to do that.