Oh, it's definitely a problem larger than Trump, and it definitely predates the Trump administration. However, I wouldn't call "gridlock" the cause. It's more like a symptom of the same underlying problem that is causing the lack of civility. While the conventional wisdom is to call this underlying problem partisanship, I think it's actually deeper than that. It's more like cross-cultural antipathy. We're in a culture war right now. It's urban v. rural, young v. old, secular v. religious, white v. non-white. This antipathy, which is inevitable in any remotely pluralistic society, has been greatly exacerbated by hateful propaganda, with the internet providing an unprecedented forum to perpetuate it.