Recent polling shows Markey’s support among Massachusetts Democratic and unenrolled voters is a little shakier than he would like. He has support among 44 percent of voters, but about as many voters say they are undecided about who they would vote for in a primary, according to a recent Boston Globe and Suffolk University poll.

The senator’s favorability rating is an anemic 38 percent, with 25 percent of voters expressing an unfavorable view of him. More than a third of voters are either undecided (22 percent) or have never heard of him (14 percent), a bad omen for a pol who’s been in Congress for more than 40 years.

“You look at that, and the fact is basically that’s a Senate seat waiting for someone to take it. If a name candidate got in today, whether it’s Rep. Joe Kennedy III, Attorney General Maura Healey or Mayor Marty Walsh, anybody, Ed Markey would have the race of his life in a presidential year,” Marsh said.