INDIANAPOLIS -- Ahead of Tuesday's primaries in Indiana, Bernie Sanders joined thousands of protesters outside a Carrier factory in the state's capital.

Sanders' message of economic inequality resonated with the union crowd Friday in Indianapolis.

Bernie Sanders speaks to Carrier union protesters CBS News

United Technologies owns Carrier. Its Indianapolis plant, which makes furnaces, gained national attention in February when a secretly recorded cell phone video became public. It showed a manager telling workers the plant will close.

A still from a secretly recorded video shows Carrier workers reacting to the news their jobs will be moved to Mexico Lakeisha Austin

"To move our production from Indianapolis to Monterrey, Mexico, this was a business decision," the manager told employees over shouts and loud boos.

When the plant closes, 1,400 employees will lose their jobs.

Lakeisha Austin, a carrier assembly worker, shot the video. "I just don't see the point of them moving when they profited so much."

Carrier's union says its Indianapolis workers average $34 an hour with benefits, and Mexican employees will make $6 dollars an hour with benefits.

The company refused to discuss wages, but did issue a statement saying out-sourcing "will allow us to operate more cost-effectively... we recognize the impact on employees, their families and the community."

Presidential campaigns pounced from the left and right. "Carrier will not leave Indiana if I'm president," Donald Trump said.

"I've read about Carrier, and I've got a set of plans that will incentiveize companies to treat workers like the assets they are," Clinton told a campaign rally.

Cruz said if he wins the presidency, "we're going to see Carrier bringing their jobs back to Indiana."

"I believe it's all political B.S.," said Frank Staples, who has worked there for eleven years.

Fellow employee Vicky Burrus has been there for for twenty. "[I'm going to] pray that I can get another job somewhere till my time, retirement time."

"They're a good symbol of corporate greed and running for the border," Staples said of Carrier.

The plant won't be shutting down until 2019, and Carrier says it will pay up to four years college tuition for laid-off employees. Vicky Burrus told CBS News nine members of her family will lose Carrier paychecks.