Bernie Sanders could be a big help to a Hillary Clinton ticket.
And Donald Trump should steer away from any thoughts of Sarah Palin as a running mate.
Those are the key findings of a new Monmouth University Poll released Thursday morning. The survey tested 12 possible running-mates for the presumptive presidential nominees from June 15-19.
Most would have little impact on Clinton or Trump.
"Two names do stand out, however," the poll found. "Bernie Sanders, who could attract undecided voters to the Democratic column, and Sarah Palin, who could potentially hurt the GOP ticket."
Thirty-nine percent of voters say that should Sanders, who finished a close second to Clinton for the nomination, join her ticket, they'd be more likely to vote for it.
Among undecided or those leaning Democratic, half say they'd be more likely to vote for Clinton if Sanders is her ticket-mate.
You have to wonder what may have happened if Rubio had not changed his mind about running for re-election to his Senate seat
Patrick Murray, director, Monmouth University Polling Institute
On the Republican side, Trump needs to stay away from Palin, the 2008 GOP vice presidential nominee and a vocal Trump backer. More than four in 10 voters said they'd be less likely to back Trump if Palin was his running mate.
Other potential Democratic and Republican picks are less well known. Clinton is said to be considering Sen. Elizabeth Warren, D-Mass, who would have only a slightly positive impact.
Others, such as Sens. Cory Booker, D-N.J. and Tim Kaine, D-Va., and Housing and Urban Development Secretary Julian Castro, are not well known.
On the GOP side, Sen. Marco Rubio,R-Fla., who said this week he plans to seek re-election to his Senate seat, had a net positive. Sens. Jeff Sessions, R-Ala., and Joni Ernst, R-Iowa, are not well known.
Former House Speaker Newt Gingrich is known, and would have a somewhat net negative impact. So would Chris Christie, the governor of New Jersey.
David Lightman: 202-383-6101, @lightmandavid