Recently, Mayor Bill de Blasio formally endorsed Hillary Clinton for president. “We have to restore the middle class,” the mayor said in an interview on Morning Joe, “and Hillary Clinton knows how to do it, will get it done, and has a progressive platform that speaks to all the changes we need, including progressive taxation.” The mayor obviously feels pressure because he is, at once, a longtime associate of Clinton and one of the nation’s leading advocates for a serious approach to issues of income inequality, and economic and social injustice. By making this endorsement, de Blasio gets on the Clinton team and closer to the inner circle (although that circle includes folks closely allied with some of his rivals). That’s good for him, good for New York, good for an urban agenda.

But there’s a downside. Clinton has already shown a willingness to move on big economic issues (trade, banks, etc.), and it is because of pressure not just from Senator Bernie Sanders but also from Senator Elizabeth Warren and people like de Blasio. Keeping that pressure on at this point is critical. If Clinton decides she has done enough, she may well not move on any more issues. She may begin to backtrack. That’s not just bad for the issues, it’s bad for Clinton. By waiting, de Blasio would have given space to Sanders, who, the mayor said, “has moved the discussion of this country in a very productive way,” and to progressive mayors and others to keep the pressure on. Why not endorse Clinton when it is clear that she has moved even more vigorously toward progressive economic positions that can excite and mobilize voters?

I believe there is still room for Clinton to move, and while understanding the tough position Mayor de Blasio is in, I think it would have been wise, tactically and morally, to keep the pressure on for that movement.