It's not only Republicans that are feeling the heat in their hometowns during this congressional recess. Democrats who aren't on board with increasingly popular progressive proposals are being held to account as well.

Sen. Dianne Feinstein (D-Calif.) was a case-in-point on Monday, when she faced angry and vocal constituents at a midday town hall meeting in her hometown of San Francisco.

It was her stance on single-payer healthcare—an idea that's picking up momentum in the wake of last month's TrumpCare debacle, especially in California—that drew the most vociferous response.

When asked about her position on such a system, Feinstein responded: "If single-payer healthcare is going to mean the complete takeover by the government of all healthcare, I am not there."