Supporters of socialist Sen. Bernie Sanders (I-VT) are delighted that his signature policy, “Medicare for All,” has become the default for much of the rest of the Democratic presidential field. They are also happy to see his other ideas, such as government-guaranteed jobs, adopted into the Green New Deal, which most candidates also support.

But many are frustrated that Sanders now faces competition from rivals too timid to embrace those policies before.

Former Ohio state senator Nina Turner told an audience of Sanders supporters at a rally in Santa Monica, California, on Friday that some of his rivals were latecomers to the progressive cause.

“For some of these folks — I’m trying to understand: did they believe all along, or of they believe just because they’re running for president?” she asked, drawing applause from the crowd of over 1,000.

Another warmup speaker, Pacific Palisades Democratic Club president Erika Feresten, also criticized those who have adopted Sanders’s “Medicare for All” policy — which he was the first to introduce — saying that many were merely co-opting his label.

Sanders has refrained from attacking most of his rivals directly — save for former Vice President Joe Biden, whom Sanders has criticized for voting to authorize the Iraq War. But his supporters are angry that the media are boosting rivals — like Sen. Elizabeth Warren (D-CA) — at his expense, when he was first to propose ideas they have adopted.

CNN seems to be playing up the Sanders-Waren rivalry. The two will face off in the center of the stage on the first night of the second Democratic debate in Detroit on Tuesday. The contrast seems deliberate: Warren is described frequently as a “younger” version of Sanders, though she is also in her seventies and is not a self-declared socialist.

On Sunday, Sanders took a group of insulin patients to Canada to highlight the problem of high prescription drug prices in the U.S. — though drug prices have declined under President Donald Trump, for the first time in 47 years.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He earned an A.B. in Social Studies and Environmental Science and Public Policy from Harvard College, and a J.D. from Harvard Law School. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.