He's running. She's running. Everyone's running.

4. The very serious senators

Let’s rank them in order of electoral seriousness: Bernie Sanders (Vt.), Amy Klobuchar (Minn.), Sherrod Brown (Ohio), Kamala Harris (Calif.), Kirsten Gillibrand (N.Y.), Cory Booker (N.J.), and Elizabeth Warren (Mass.). Aside from Sanders, who towers above the rest of the pack by virtue of having ignited a left-wing insurgency in the party that rages on to this day, I’m fonder of those who don’t hail from the Northeast, with Klobuchar and Brown showing the greatest broad-based potential among those who aren’t socialists from Brooklyn. But all of these options deserve be taken seriously; all are likely to make it into the early A-list primary debates.

5. The brand-boosters

Rumor has it that Donald Trump initially ran for president not to win but simply to raise his public profile and enhance his ability to monetize his name. Actually winning was just a bonus. There are usually a few people who stick their toes in the water early on to enhance their public stature, and this time around there may be far more than a few — perhaps a baker’s dozen, in fact. So far all of the following people have at least expressed an interest in running: Montana Gov. Steve Bullock, Obama HUD Director Julian Cástro, Rep. John Delaney (Md.), Los Angeles Mayor Eric Garcetti, Colorado Gov. John Hickenlooper, Obama Attorney General Eric Holder, former New Orleans Mayor Mitch Landrieu, former Virginia Gov. Terry McAuliffe, Sen. Jeff Merkley (Ore.), Sen. Chris Murphy (Conn.), former Maryland Gov. Martin O’Malley, former Massachusetts Gov. Deval Patrick, and Rep. Tim Ryan (Ohio).