COURTLAND, Ala. — In this forlorn Southern town whose once-humming factories were battered in recent years by a flood of Asian imports, Rhonda Hughes, 43, is a fervent supporter of Donald Trump. Her 72-year old mother is equally passionate about Senator Bernie Sanders.

Disenchantment with the political mainstream is no surprise. But research to be unveiled this week by four leading academic economists suggests that the damage to manufacturing jobs from a sharp acceleration in globalization since the turn of the century has contributed heavily to the nation’s bitter political divide.

Ms. Hughes avoids discussing the election with her mother, but their neighbor Benjamin Green, 83, knows just what Washington needs. “It’ll take a junkyard dog to straighten this country out,” he said.

Cross-referencing congressional voting records and district-by-district patterns of job losses and other economic trends between 2002 and 2010, the researchers found that areas hardest hit by trade shocks were much more likely to move to the far right or the far left politically.