 There are, of course, those who ran last time who might jump back in, in theory, Senator Cory Booker, Senator Amy Klobuchar, potentially even maybe Pete Buttigieg, who is currently the transportation secretary. But the ones who are going to have the best chance are those who have an apparatus already, who have a set of donors and fundraisers who can raise money instantly and who have the ability to get on TV and get media attention without having to work as hard for it.