WASHINGTON (NEXSTAR) – Some Senators say workers across the country should have the right to unionize so they can bargain for better wages, benefits, and working conditions.

“You need to shut your mouth,” Sen. Markwayne Mullin (R-Okla.) said.

“A real tough guy. You’re gonna tell me to shut my mouth?” International Brotherhood of Teamsters General President Sean O’Brien said.

Sparks flew as Senators questioned experts on workers’ rights to unionize. Mullin accused some unions of just taking people’s paychecks.

“You wanna say you’re trying to provide because you’re forcing them to pay dues,” Mullin said.

“No, we don’t force them to pay dues. You’re out of line,” O’Brien rebutted.

“Don’t tell me I’m out of line,” Mullin said.

Sen. Roger Marshall (R-Kan.) doesn’t think unions are a problem but doesn’t want them to have more power in right-to-work states.

“In Kansas, we have a pretty good relationship going on that allows the franchise model, allows the unions. I’m concerned when the federal government gets two involved,” Marshall said.

But other lawmakers say some states make it too difficult to join a union, hurting workers’ chances to negotiate better pay and benefits.

“If a worker alone is in trouble, he or she does not have a lot of power to ask for better wages,” Sen. Bernie Sanders (I-Vt.) said.

Sanders says for many workers, it can make a huge difference in their life and prevents corporations from taking advantage of workers.

“What does it mean to a worker who’s making starvation wages when they’re able to join a union,” Sanders asked.

“It means a shot at a better life for themselves and their children,” Service Employees International Union International President Mary Kay Henry said.

The committee will revisit the issue in a few weeks, when the CEO of Starbucks, an opponent to unions, comes to Capitol Hill to testify.