From left to right, Cory Booker, Kirsten Gillibrand, Amy Klobuchar, Kamala Harris and John Hickenlooper (JTA Collage; Booker Photo: Alex Edelman/Getty Images; Gillibrand Photo: Chip Somodevilla/Getty Images; Klobuchar Photo: Theo Wargo/Getty Images for DGA; Harris Photo: Chip Somodevilla/Getty Images; Hickenlooper Photo: Chip Somodevilla/Getty Images)