The swearing-in of a new Senate has ignited what might be the final battle in the fight to either save or repeal the Affordable Care Act. Though he's been critical of some of the healthcare reform law's shortcomings in the past, Vermont Senator Bernie Sanders is not going to let it go down without a fight.

Sanders used the debate to hold President-elect Donald Trump to fire for one of his major healthcare promises.

Sanders presented a print out a May 2015 tweet by Donald Trump as a giant poster and used it as a prop to remind voters Trump had once promised to protect Medicare and Medicaid.

In the tweet, Trump, who hadn't yet announced he'd be running for president (that would happen a month later), announced he'd never cut the social safety net relied upon by so many older and lower-income Americans. He also used it to take a shot at former Arkansas governor Mike Huckabee, rumored to be running for president as well.

A repeal of the Affordable Care Act would entail rolling back a major expansion of Medicaid - something Trump vowed he wouldn't do.

“Millions of people voted for him on the belief that he would keep his word,” Sanders said during his speech. “If he was sincere, then I would hope that tomorrow or maybe today he could send out a tweet and tell his Republican colleagues to stop wasting their time and all of our time.

Note: An earlier version of this story erroneously reported that the repeal of Obamacare would entail rolling back the expansion of Medicare. In fact, the Affordable Care Act included a significant expansion of Medicaid, which is the U.S. government's healthcare program for low income families. Medicare, which is a healthcare program for people over the age of 65, was not expanded under Obamacare.