Oh he's with Allstate?
This is what they have to say about defamation being covered by their umbrella policy:
Source
I'll quote the important bit:
WHAT TYPE OF DEFAMATION IS NOT COVERED BY A PERSONAL UMBRELLA POLICY?
While an umbrella policy may help prevent you from paying out of pocket if you face a legal judgment for defamation, not every scenario is covered by a personal umbrella policy. Here are a few typical exclusions:
- Your alleged libelous or slanderous statement is related to a business you own
- Your policy wasn't in force at the time the comment was said or written
- You intentionally make a false comment or statement that defames someone else
Gonna guess that they might not look too kindly on Ron's tweeting habits.