Over at Jacobin, Samuel Stein has a review of Eric Alterman’s new book on Bill de Blasio’s first year as mayor. The whole piece by Stein is worth a read, in no small part because de Blasio has been held up as a populist progressive icon of the highest calibre, with little scrutiny on his whole body of work or how well his actual policies reflect on a rising left populist movement in America. But Stein’s closing line strikes me as critically important, not just for how the left thinks of de Blasio, but any Democratic politician.

Praising the mayor for his genuinely progressive accomplishments while discounting or disregarding his conservatism isn’t merely a cop-out. It’s a lie. It dances around the perils of his programs. And it puts the Left in the position of defending a figure it should be fighting.

To put it differently, politicians contain multitudes. Just because someone is good on one set of issues – rhetorically or in practice – doesn’t mean that they’re good on all issues. Elizabeth Warren is a brilliant advocate for the middle class, for breaking up Wall Street banks, and fighting rampant corporate power. But she’s pretty milquetoast on, say, foreign policy and has adopted some very establishment positions as a sitting senator that many on the left would disagree with. Likewise Howard Dean’s vocal opposition to the war in Iraq was critically important for the liberal wing of the Democratic Party in 2003-2004, while today he lobbies for Big Pharma and is squarely in Hillary Clinton’s corner. I say this not as a reflexive discount of Clinton, who will certainly be good on some issues and bad on others, but as a recognition that Dean is a fairly centrist Democrat who happened to be right on the Iraq War.

Politicians serve the public. They serve as ciphers for the political ideologies ascribed to them. It does no political movement any good to let politicians get away with behaviors that reflect negatively or are diametrically opposed to the movements they are presumed to represent. Celebrate a politician when it is deserved and criticize when it is deserved – that’s the role of a movement.