Yes. Seriously, these rallies should not be cancelled. They're a big reason why this virus just happened to appear right now.

A few rules wouldn't hurt, like no handshaking with POTUS this time. Just wave or do the Vulcan salute (live long & prosper!) Maybe give all attendees a little bottle of hand sanitizer.

And it would be sensible for anyone in a high risk group to stay home this time. Otherwise? No. Keep the rallies going! The virus will spread anyway. Just take some precautions as advised and live your life.