Chris Murphy broke through the gridlock on guns. He’s not done.

The Connecticut senator guided a gun safety package through Congress after years of trying. Colleagues credit him for listening, and not letting the perfect be the enemy of the good. Part 1 of 2.

Clad in running shoes and a UConn baseball cap, Sen. Chris Murphy walks along the shoulder of a two-lane road, a red umbrella bobbing above his head. Occasionally, he’s splashed by a passing car. 

The junior senator is on his sixth “Walk Across Connecticut,” in which he treks from one end of his state to the other, talking with voters and taking selfies along the way. It’s the kind of event that politicians often invite the press to cover. But Mr. Murphy, his team warns, likes to walk alone.

For the past decade, he has approached his quest to curb America’s gun violence in much the same way: one dogged step at a time, and often by himself. 

Ever since 2012, when the then-congressman found himself consoling devastated parents outside Sandy Hook Elementary School in Newtown following one of the worst mass shootings in American history, Mr. Murphy has immersed himself in the gun issue. He learned from activists, wrote a book, and tried to get Congress to pass gun safety legislation – to no avail.