As someone else said, O'Rourke/Warren would be strong, but vice versa is not. Pence is an easier pill to swallow than Trump, and many of the McMullin/Johnson/write-in Republicans of 2016 are more willing to vote for President Mike Pence. As a result, Pence performs better in the Great Plains, west, and south, however due to fervent social conservatism, underperforms Trump in New England. Warren is able to win Michigan by 4.7 points, and Wisconsin by a slim half-point.
President Mike Pence (R-IN)/Vice President Nikki Haley (R-SC) - 308 EV (50.2%)Senator Elizabeth Warren (D-MA)/Senator Beto O'Rourke (D-TX) - 230 EV (47.9%)