U.S. political divide becomes increasingly violent, rattling activists and police

TYLER, Tex. — The goal of the rally was to oppose the deployment of federal agents to quell protests in American cities — and to register new Democratic voters here in the heart of conservative East Texas.

But it had hardly begun when hundreds of conservative counterprotesters and supporters of President Trump, many with military-style rifles slung over their shoulders, swarmed the town square and began pushing and shoving and yelling obscenities.

One man punched Democrat Nancy Nichols in the chest, she said, and three others pinned her husband against...