First they get a basketball team, now they want a convention?

The de Blasio administration on Friday proposed that when the Democratic Party gathers to crown its next presidential nominee, it do so in the mayor’s home borough, a cradle of the resurgent left that has morphed from a symbol of the working class into a gritty, global arbiter of cool.

In a 200-page formal bid, New York City offers up the Barclays Center, the rust-glazed sports and entertainment arena near Brooklyn’s bustling downtown, as the anchor venue for the quadrennial gathering, with accommodations and other events to be spread across the city’s four other boroughs.

One big problem. All the nice hotels are in Manhattan:

But hotel rooms could be an issue: Brooklyn has 3,500 of them, about 10 percent of the convention’s expected turnout. To bolster its bid, New York officials took pains to cite a variety of budget accommodations across the city, including a Howard Johnson in Queens Village and several hotels near La Guardia Airport. The city’s public-transit network would be used to shuttle delegates to and from events.

And memo to de Blasio: Delegates don’t take public transportation.