Abdul El-Sayed (centre), a leftist former medical administrator, has built his political identity around a pledge to provide free healthcare for all Americans. (AFP pic)DETROIT: Abdul El-Sayed, the doctor seeking a must-win US Senate seat for the Democrats, fired up a packed crowd of supporters in Detroit with a cry of "give it up for public health."

El-Sayed, a leftist former medical administrator who became the surprise candidate in Michigan's Senate race, has built his political identity around a pledge to make healthcare free for all Americans.

"You deserve to be able to see a doctor without getting a huge bill on the back," he said on the eve of midterm elections that could change the course of Donald Trump's presidency by taking control of Congress away from him.