Merkley, Booker and Harris’ comments exert subtle pressure on other senators seen as potential 2020 contenders, including Elizabeth Warren (D-Mass.), Bernie Sanders (I-Vt.) and Kirsten Gillibrand (D-N.Y.). Even so, Harris said in a brief interview that her Sunday comment not closing the door to a presidential run came only after persistent questioning from sustained pressure from her MSNBC interrogator: “It was not voluntary.”

In a moment of full-on political combat with Trump, not everyone sees the need to hold off on talking about any election bid as long as Barack Obama, whose White House interest was first reported in late October 2006, or Trump, whose intentions seeped into view in December 2014, did.

“The most common mantra around here is that the presidential race starts too early,” Sen. Richard Blumenthal (D-Conn.) said. “But it begins when it begins. And let’s face it, it’s never too early. Because people need to begin working, and I’m a great believer in starting whenever it feels right.”