Rejection of fascism and racism is good not just for New Yorkers, but more widely Americans. The optimist in me also likes to think that this is a signal to politicians and political parties everywhere that you can challenge far right populism and win, rather than absorbing elements of it to attract voters. (Labour continue to disappoint me in this respect)

I think the challenge for Mamdani now (as I suppose it is for any progressive who gets voted in) is actually making positive change happen at the rate that people want and need it. There will be a lot of people waiting to leap on failure, including some Democrats.