Look up the term "paddock anti trump" (preferably duckduckgo) you will see he was a registered democrat, attended democrat rallies and started loading up on guns around the time Trump was elected.

Also he targeted the country concert because there would be a high amount of conservatives there.

Whether he was a patsy or not i don't know for certain, but that's the reason they never focused on the identity of the shooter like they usually do.

Although it din't make a difference, people saw his anti-trump boomer memes on Facebook and dug into his past. The only thing is you never hear about this because it gets censored.