Sometimes the best offense is to punt before you take a safety. In this case, I think it would be better for the nation as a whole if a decent Dem gets elected who can bring us back together. The scum of from this president on the GOP makes them incapable of uniting the country at this time. Then GOP can then get their heads out of their collective behinds and start to rebuild a party that isn't taken captive by a con man and his weak knee supporters in the Congress. If Congressional GOP leaders would wise up & stop supporting Trump, there would be time for a quality candidate to step up on the GOP side But the longer they fight the obvious, the more likely they will get defeated in a landslide. I don't expect this leadership group to step up - they haven't shown the guts to do so and they have there own special interests invested into Trump.
Note: if Kasich were to run - I'd be walking the streets on his behalf. A compassionate, decent man- the opposite of Trump.