Health care is a complicated subject ― as even President Donald Trump recently admitted.

But explaining why House Republicans’ Obamacare replacement bill would make Americans’ lives worse does not have to be, according to Sen. Elizabeth Warren (D-Mass.).

Speaking to constituents at an “office hours” meeting at the public library in Worcester, Massachusetts last week, Warren test-ran a simple but devastating line of attack against GOP lawmakers who vote for the American Health Care Act, as the legislation is known.

“You want to repeal and replace ― let me see what you’re going to do with it guys,” she said, as if addressing her Republicans colleagues. “You get your plan together and see how it works and you come explain to the American people how 24 million of them lost coverage.”

“You come explain to the families all over my state that have lost a loved one to opioids how you’re going to suck $5 billion out of treatment for opioid addiction. You go explain that,” she continued, drawing applause.

Watch her complete remarks in the video below:

When the Republicans say they want to repeal health care for 24 million people today, they need to explain this. pic.twitter.com/gjyE6oVWuk — Elizabeth Warren (@elizabethforma) March 23, 2017