After thinking about it a little more, here’s my quick and dirty list of the most likely people to run for the nomination, from #1 to #24 (I’ve probably forgotten a few names though):
1 O’Malley
2 Booker
3 Gillibrand
4 Warren
5 Castro
6 Cuomo
7 Klobuchar
8 Sanders
9 Brown
10 Biden
11 de Blasio
12 Harris
13 Hickenlooper
14 Gabbard
15 Franken
16 Kander
17 Murphy
18 Bullock
19 Malloy
20 Clinton
21 Kerry
22 Patrick
23 Kaine
24 Sandberg
That's a pretty solid list. This would be what I would say:
1. O'Malley
2. Cuomo
3. Booker
4. Gillibrand
5. Klobuchar
6. Warren
7. Harris
8. Castro
9. Gabbard
10. Sanders
11. Brown
12. Murphy
13. Hickenlooper
14. Clinton
15. de Blasio
16. Kander
17. Franken
18. Bullock
19. Biden
20. Patrick
21. Sandberg
22. Malloy
23. Kerry
24. Kaine