Sorry, but Reagan’s behavior in the 1980s was acceptable and effective.
In the 2010s, not effective.
Like it or not, but what Trump is doing re: social media, leverage, and walking away publicly is exceptionally effective.
Your candidate isn’t effective.
You might not like it, but that’s how the world works today, and your candidate will keep losing unless he figures that out too.
So you have a choice. Stay clean and lose, or get dirty and win?