Democrats have a message for Bernie Sanders: Shut it down before the July national convention in Philadelphia.

That’s according to The POLITICO Caucus — a panel of activists, strategists and operatives in 10 key battleground states — who worried a protracted post-primary clash for the nomination could hurt Hillary Clinton, the party’s likely nominee, in their states in the general election.


Half of Democratic insiders said Sanders, who trails in the delegate race by a wide margin, should end his campaign before the final primary on June 14 in the District of Columbia. Another 39 percent said the Vermont senator should continue campaigning through the D.C. primary, but end his campaign immediately after if he trails Clinton in pledged delegates — which is likely given Sanders’ current deficit of 277 pledged delegates after Clinton’s resounding victory in New York this week.

Only 1 in 10 Democratic insiders said Sanders should try to woo superdelegates to help him overtake Clinton on the convention floor in Philadelphia if he finishes the primary season trailing in pledged delegates, as campaign manager Jeff Weaver suggested Tuesday night in a televised interview.

“I think it would benefit the Democrats to have Bernie drop out sooner rather than later and ask his supporters to coalesce behind Hilary,” said a Wisconsin Democrat, who, like all respondents, completed the survey anonymously. “He stands no chance of winning the nomination at this point, and the Democrats can show a united front while the Republicans are so deeply fractured.”

“Bernie made his point,” added one Colorado Democrat. “It's time to bring the party back together. The longer he waits, the more damage he does. The question is whether or not he cares. The rest of us do.”

A Nevada Democrat suggested the Sanders camp should focus on “doing what’s necessary for a Democratic victory in November,” but said Weaver “made a fool of himself by declaring on MSNBC that Bernie would take the campaign to the convention even if they were behind in delegates and popular vote.”

Some insiders suggested a graceful exit could help Sanders — the independent junior Vermont senator — become a major player in Democratic politics in the years to come.

“The primary is over. There is no path, and there is no math,” added one Florida Democrat. “The sooner he lands the plane, the better chance he has at building a real legacy from this.”

And a number of Democrats sounded a note of exasperation with Sanders’ campaign — and the senator’s supporters.

“If any adults actually supported Bernie, they would tell him to get out next Wednesday morning,” said a New Hampshire Democrat. “But he doesn't have any adult supporters. So he will stay in.”

“He should also do what Hillary did in '08 — support her and convince his followers to do the same,” added a Wisconsin Democrat. “Here in Wisconsin, we have Bernie supporters posting things on Facebook like, ‘I'm not voting for [Democratic Senate candidate] Russ Feingold because I heard he is supporting Hillary.’ I'm not hearing any of those sentiments from Hillary supporters, and if Bernie gets the nod, I know her people will work for him, no question.”

Republicans, meanwhile, are having fun with the protracted fight on the other side of the aisle.

“Why should the Republicans have all the fun with a contested convention?” asked one Pennsylvanian.

Two other takeaways from this week’s survey:

Republicans: Trump is the most likely nominee.

With the Republican race barreling toward a contested convention, GOP insiders in the 10 swing states say Donald Trump is the favorite to win the nomination.

Fifty-six percent of insiders said Trump is the party’s most likely nominee, with a third picking Ted Cruz. The remaining insiders chose either John Kasich (6 percent) or “someone else” (5 percent).

This week revisited a similar question asked in late February, following consecutive Trump victories in New Hampshire, South Carolina and Nevada. Then, more than 8 in 10 insiders said Trump was the party’s most likely nominee, with 17 percent choosing Florida Sen. Marco Rubio.

One Iowa Republican cited the increased professionalization of Trump’s campaign — including the installation of longtime GOP hand Paul Manafort to run much of the real-estate tycoon’s political operation — as evidence Trump could secure the 1,237 delegates to win the nomination.

“There is a definite pre- and post-Manafort feel to this,” the Republican said. “Two weeks ago, it felt like Ted Cruz had it sewn up. Trump got smart and played Cruz's game — they are now effectively each blocking the other from getting to 1,237, but Trump is closer and can still put it over the top.”

Another Iowa Republican pointed to Trump’s blowout victory in New York this week as an indication that Trump’s chances were improving.

“I've changed on this,” the Republican said. “I thought Cruz was the likely nominee until this past week. Donald Trump appears to have gained a slight edge, with a big New York win and five states next week he's expected to win. While he continues to lose to Cruz in hand-to-hand combat fighting for delegates at the state level, he's winning the message war and laying the groundwork to make it difficult to take the nomination away in Cleveland.”

A Colorado Republican said even if Trump doesn’t have 1,237 delegates bound to him on the first ballot, he could end up close enough that he could bring in enough unbound delegates to put him over the top.

“Donald Trump is likely to fall a handful of votes short of the 1,237 needed in officially pledged delegates to secure the nomination outright as a result of the primary contests that remain, but if he is only a few votes short, the 168 unpledged RNC members will be under enormous public pressure to defer to history and the electorate and push him across the finish line in Cleveland,” the Colorado Republican said. “If Trump finds himself more than 100 or 150 votes short, it is much less likely that the RNC members will feel a sense of obligation to award the nomination to the front-runner, and Cruz will take the nomination on the second or third ballot.”

But a Pennsylvania Republican disagreed, predicting those delegates wouldn’t go Trump’s way.

“At a contested convention, Cruz will outsmart and out-organize Trump,” the Pennsylvania Republican said. “Delegates are not the same as voters.”

Clinton, Trump favored to win Pennsylvania.

This week’s survey included interviews with a dozen insiders in Pennsylvania, which holds its primaries on Tuesday. And the vote was nearly unanimous: All 12 expect Clinton to carry the state, while 11 said Trump would win the Republican primary.

“Clinton is going to put the fork into Sanders in Pennsylvania,” said one Democrat. “This state is tailor-made for her. The Clintons are undefeated in Pennsylvania, she claims Scranton as a home, her son-in-law is from Philadelphia.”

“The Clinton family has been good to Pennsylvania, and we have been good back to them,” added another Democrat. “She will win with a pretty big margin, closer to 10 points (and maybe more) than it will be to 5 points.”

On the Republican side, nearly all the Pennsylvania insiders picked Trump to win, though one held out for Kasich.

“This is still Trump's race, but it will not be the blowout people expected just a month ago,” predicted one Republican. “Kasich will surprise as well.”

“Unfortunately, the Cruz campaign has missed their opportunity to capitalize on Trump’s stumbles and increasingly people are looking at Kasich as an alternative,” added another Republican. “This split in the anti-Trump vote will be enough to get him across the finish line. Campaigns matter, and the Cruz campaign is just not doing what it needs to do to win.”

Pennsylvania insiders split evenly, however, on the Democratic Senate primary next week between former Rep. Joe Sestak and 2014 gubernatorial candidate Katie McGinty; the winner will face incumbent GOP Sen. Pat Toomey in a race that could determine which party controls the Senate next year.

"McGinty just hasn't run a campaign that really stands out," said a Democrat who picked Sestak, who is seeking a rematch with Toomey after losing the 2010 contest. "The amount of money outside groups are spending is impressive, but does money matter if the ads aren't very good?"

But some Republicans predicted McGinty would emerge because Sestak has eschewed attacking his main opponent.

"McGinty will win because Joe Sestak refused to punch back and go negative," one Republican said. "This was Joe Sestak's primary to lose."

These are the members of The POLITICO Caucus, not all of whom participated in this survey:

Colorado: Adam Eichberg, Alan Salazar, Andrew Freedman, B.J. Nikkel, Craig Hughes, Cole Finegan, Frank McNulty, Janice Sinden, Karen Middleton, Laura Carno, Matt Chandler, Mark Ferrandino, Michael Fortney, Owen Loftus, Pat Steadman, Pat Waak, Pete Maysmith, Rick Ridder, Rob Witwer, Roxane White, Ryan Call, Steve Welchert, Taylor West, Ted Harvey, Will Coyne

Florida: Alia Faraj-Johnson, Andrea Reilly, Andrew Weinstein, Andrew Wiggins, April Schiff, Ashley Walker, Ben Pollara, Beth Matuga, Brian E. Crowley, Chris Korge, Christian Ulvert, Damien Filer, David Beattie, David Johnson, Dennis Baxley, Elizabeth Cuevas-Nuender, Eric Johnson, Eric Jotkoff, Fernand R. Amandi, Fred Menachem, Gus Corbella, Jacki Lee, Jessica D. Ehrlich, Joe Mobley, John Dowless, Jon Mills, Joseph Falk, Judith Diaz, Justin Day, Kelly Cohen, Kevin Cate, Kevin Sweeny, Marian Johnson, Mark Ferrulo, Marty Fiorentino, Max Steele, Nelson Diaz, Nick Iarossi, Pamela Burch Fort, Rich Heffley, Richard R. Swann, Rick Wilson, Roger Stone, Ronald L. Book, Ryan Duffy, Ryan Wiggins, Scott Arceneaux, Slater Bayliss, Steve Schale, Steven Vancore, Susan A. MacManus, Tim Baker, Wayne Bertsch

Iowa: Tim Albrecht, Brad Anderson, Rob Barron, Jeff Boeyink, Bonnie Campbell, Dave Caris, Sam Clovis, Sara Craig, Jerry Crawford, John Davis, Steve Deace, John Deeth, Derek Eadon, Ed Failor Jr., Karen Fesler, David Fischer, Doug Gross, Steve Grubbs, Tim Hagle, Bob Haus, Joe Henry, Drew Ivers, Jill June, Lori Jungling, Jeff Kaufmann, Brian Kennedy, Jake Ketzner, David Kochel, Chris Larimer, Chuck Larson, Jill Latham, Jeff Link, Dave Loebsack, Mark Lucas, Liz Mathis, Jan Michelson, Chad Olsen, David Oman, Matt Paul, Marlys Popma, Troy Price, Christopher Rants, Kim Reem, Craig Robinson, Sam Roecker, David Roederer, Nick Ryan, Tamara Scott, Joni Scotter, Karen Slifka, John Smith, AJ Spiker, Norm Sterzenbach, John Stineman, Matt Strawn, Phil Valenziano, Jessica Vanden Berg, Nate Willems, Eric Woolson, Grant Young

Nevada: Adam Khan, Andres Ramirez, Andrew Diss, Barbara Buckley, Bob Cavazos, Brendan Summers, Chip Evans, Chuck Muth, Dan Hart, Daniel Stewart, Ed Williams, Emmy Ruiz, Erven T. Nelson, Greg Bailor, Heidi Wixom, Jack St. Martin, James Smack, Jay Gertsema, Jeremy Hughes, Jim DeGraffenreid, Jon Ralston, Kristen Orthman, Laura Martin, Linda Cavazos, Lindsey Jydstrup, Mac Abrams, Mari St. Martin, Marla Turner, Megan Jones, Michael McDonald, Michelle White, Mike Slanker, Neal Patel, Nick Phillips, Oscar Goodman, Pat Hickey, Paul Smith, Pete Ernaut, Peter Koltak, Riley Sutton, Robert Uithoven, Roberta Lange, Ryan Erwin, Ryan Hamilton, Sam Lieberman, Scott Scheid, Yvanna Cancela, Zach Hudson

New Hampshire: Charlie Arlinghaus, Arnie Arnesen, Patrick Arnold, Rich Ashooh, Dean Barker, Juliana Bergeron, D.J. Bettencourt, Michael Biundo, Ray Buckley, Peter Burling, Jamie Burnett, Debby Butler, Dave Carney, Jackie Cilley, Catherine Corkery, Garth Corriveau, Fergus Cullen, Lou D’Allesandro, James Demers, Mike Dennehy, Sean Downey, Steve Duprey, JoAnn Fenton, Jennifer Frizzell, Martha Fuller Clark, Amanda Grady Sexton, Jack Heath, Gary Hirshberg, Jennifer Horn, Peter Kavanaugh, Joe Keefe, Rich Killion, Harrell Kirstein, Sylvia Larsen, Joel Maiola, Kate Malloy Corriveau, Maureen Manning, Steve Marchand, Tory Mazzola, Jim Merrill, Jayne Millerick, Claira Monier, Greg Moore, Matt Mowers, Terie Norelli, Chris Pappas, Liz Purdy, Tom Rath, Colin Reed, Jim Rubens, Andy Sanborn, Dante Scala, William Shaheen, Stefany Shaheen, Carol Shea-Porter, Terry Shumaker, Andy Smith, Craig Stevens, Kathy Sullivan, Chris Sununu, James Sununu, Jay Surdukowski, Donna Sytek, Kari Thurman, Colin Van Ostern, Deb Vanderbeek, Mike Vlacich, Ryan Williams

North Carolina: Anita S. Earls, Brad Thompson, Bruce Thompson, Charles Wallin, Christopher Sgro, Dee Stewart, Douglas Wilson, Dylan Frick, Francis X. De Luca, Jonathan Felts, Melissa Reed, Michael Luethy, Morgan Jackson, Paul Shumaker, Patsy Keever, Ray Martin, Robin Hayes, Tami Fitzgerald, Taylor Griffin, Theresa Kostrzewa, Thomas Mills

Ohio: Bill DeMora, Bob Clegg, Cindy Demse, Damareo Cooper, David Leland, David Pepper, Erica Bruton, Greg Beswick, Ian James, Jai Chabria, Janet Carson, Jo Ann Davidson, Joe Hallett, Kathy DiCristofaro, Katie Eagan, Mark R. Weaver, Martha Clark, Matt Borges, Melissa Klide Hedden, Michael Gonidakis, Mike Dawson, Molly Shack, Nick Martin, Rhine McLin, Tim Burke, Wes Goodman

Pennsylvania: Charlie Gerow, Christopher Nicholas, Christopher P. Borick, Daniel F. Fee, David P. Sosar, David Thornburgh, Doc Sweitzer, Jason Ercole, Larry Ceisler, Marcel Groen, Mark Harris, Nachama Soloveichik, Ray Zaborney, Todd Stephens, Valentino DiGiorgio

Virginia: Abbi Easter, Bob Marshall, Brian Coy, Carolyn Fiddler, Chris LaCivita, Doris Crouse-Mays, Ed Matricardi, Frank Leone, Gaylene Kanoyton, Janet Carver, Jeannemarie Devoltes Davis, Jo Thoburn, Joe Fitzgerald, John Crosgrove, John Findlay, Marc Broklawski, Margo Horner, Michael Farris, Patsy Brown, Pete Snyder, Ray Allen, Sandra Brandt, Steve Stombres, Sue Langley, Susan J. Rowland, Susan Swecker, Tom Davis, Tucker Martin

Wisconsin: Barry Burden, Brandon Scholz, Emily Nehring, Gary B. Hawley, Jason Rae, Jim Camery, John T. Zaphfel, Kevin Barthel, Meg Andrietsch, Marian Krumberger, Mary Arnold, Michael Basford, Patrick Guarasci, Rebecca Bonesteel, Robert Hansen, Terri Burl

Kristen Hayford contributed to this report.

