Rep. Nancy Pelosi (D-CA) warned the field of 2020 Democratic presidential nominees that they should resist the urge to move leftward, suggesting that the party cannot win in key states like Wisconsin, Michigan, and Ohio with a severely progressive platform.

Speaking at a Bloomberg News roundtable on Friday, Pelosi mocked the liberal ideas, like “Medicare for All,” that candidates like Sen. Bernie Sanders (I-VT) and Sen. Elizabeth Warren (D-MA) are using to fire up Democrats on social media, noting that what wins in her home district in San Francisco, California, isn’t what wins in states where Democrats have struggled to remain compeitive, and where voter bases are more moderate.

Instead, Pelosi said, Democrats should focus on what wins in the Rust Belt, because voters in decidedly “blue” states will respond to those policies, too.

“What works in San Francisco does not necessarily work in Michigan,” Pelosi said, according to Yahoo News. “What works in Michigan works in San Francisco — talking about workers’ rights and sharing prosperity.”

“Remember November,” Pelosi added. “You must win the Electoral College.”

She’s not wrong. Democrats learned in 2016 that the Rust Belt was more volatile than expected; blue collar, working class Democrats responded well to now-President Donald Trump’s message of economic populism and immigration control and switched parties to cast a ballot for the New York City real estate developer over 2016 Democratic presidential nominee Hillary Clinton.

States like Michigan, Wisconsin, and even Florida — where panhandle Democrats also swapped parties — ultimately cost Clinton the presidency, and Pelosi, clearly playing the long game, knows the same thing could happen if nominee Warren or Sanders pushes a platform with massive federal expansions like a “Green New Deal” or “Medicare for All.”

At Friday’s event, Pelosi also took aim at Warren’s Medicare for All proposal specifically, calling it, essentially, a pipe dream with a sky-high price tag, according to The Hill.

“I’m not a big fan of Medicare for All,” Pelosi said, referencing Warren’s signature agenda item. “I mean I welcome the debate, I think that we should have health care for all.”

“There is a comfort level that some people have with their current private insurance that they have, and if that is to be phased out, let’s talk about it, but let’s not just have one bill that would do that,” she continued, also noting that Medicare for All could be “expensive.”

“We have invited advocates for it to testify in Congress, in the Ways and Means Committee, in the Budget Committee, in the Rules Committee, being respectful of the point of view,” she explained, but, ultimately, Democrats have repeatedly declined to press the plan.

Instead, Pelosi suggested, candidates should focus on a message that incorporates “healthcare for all.”

That’s not likely. Warren is using Medicare for All to distinguish herself from other candidates in the field, and to appeal to Sen. Bernie Sanders’ base, probably on the theory that even die-hard Sanders supporters don’t believe he’s likely to be the nominee. She’s pressing the issue, though, even as critics point out that there’s no way she can pay for a Medicare for All-type system without increasing taxes on the middle class or, at least, those who fall below the threshold for being considered part of the “1%.”

Sanders is, of course, honest about the cost of his plan, suggesting that those who would see their taxes rates rise (including those in the middle class) would also see their health care costs decline, making the tax hike worthwhile.

Pelosi has been working hard to curb the more progressive members of her party for nearly two years, since a “squad” of far-left politicians, including Rep. Alexandria Ocasio-Cortez (D-NY), entered Congress. She’s tangled more than once with Ocasio-Cortez and other newly elected progressives, even over the issue of impeachment.