MISSOULA, Mont. (AP) — Vermont Sen. Bernie Sanders spoke about economic inequality and the failings of the country's health care system Saturday as he sought to rally Montanans to vote for a singing cowboy trying to become the state's first Democrat in the U.S. House in two decades.

Sanders, an Independent who defeated Hillary Clinton in Montana's Democratic presidential primary last June, urged a crowd of about 3,500 at the University of Montana in Missoula to vote for Rob Quist in Thursday's special election.

Republican Greg Gianforte and Libertarian Mark Wicks also are seeking to fill Ryan Zinke's House seat after he joined President Donald Trump's cabinet as Interior secretary.

Sanders challenged Montana voters to show that a rural state with a small population can take on the big money interests that he said are trying to buy the election.

"The eyes of the country are on Montana this week," Sanders said.

Sanders is the latest to add star power to the race. In recent weeks, Gianforte has campaigned with Vice President Mike Pence and Donald Trump Jr.

Sanders and Quist both decried efforts by Republicans to repeal and replace President Obama's Affordable Health Care Act, saying the American Health Care Act is a tax break for the rich.

"People shouldn't have to go bankrupt because they've had a medical issue," said Quist, who has come under scrutiny because of tax liens and a spate of debts.

He blamed his health care woes and high medical bills for his downward financial spiral.

In the waning days of the campaign, both sides have taken to the airwaves and the campaign trail to reinforce their campaign mantras. Gianforte has been stressing his support of gun rights, while Quist is campaigning on preserving access to health care.

Sanders also was scheduled to campaign on Quist's behalf at rallies in Butte and Billings on Saturday and in Bozeman on Sunday.