Hundreds of people who want to save the Affordable Care Act joined a group of Maine Democrats on Sunday in Portland to rally for Congress to keep the much-debated health care law.

U.S. Rep. Chellie Pingree, state Sen. Troy Jackson and state Rep. Ben Collings hosted the rally on the steps of Portland City Hall. The three Democrats are among many who have said a Republican drive to end the law is a threat to the health security of millions of Americans.

Pingree, who has advocated for regulated drug prices in the past, told the crowd that Republicans who want to repeal the law do not have a suitable replacement plan.

“They have no plans. They tell us to wait,” she said. “Can a cancer patient afford to delay their surgery to remove their tumor?”

Police estimated about 600 people attended the rally, and said the event was orderly.

The crowd spilled onto the sidewalks and traffic medians near City Hall and participants loudly jeered Republican opposition to the law, which is President Obama’s signature legislation.

“Here in Maine, we value independence. We value hard work. Health insurance gives us the peace of mind that one serious illness or event won’t lead to bankruptcy. It offers us stability in an uncertain world,” Emily Brostek, executive director for Consumers for Affordable Health Care, said in a statement issued Sunday by the Augusta-based nonprofit advocacy organization.

“Before the Affordable Care Act, too many Mainers had to gamble that they stay healthy and out of debt by going without insurance. We can’t ask Maine people to put their health on the line to cover Congress’s reckless bets,” Brostek said. “We urge Congress to let common sense prevail and reject any effort to repeal the ACA that does not include a strong, viable replacement.”

The law was derided during the presidential campaign by President-elect Donald Trump, who was another target of the crowd’s ire Sunday in Portland.

People held signs with slogans such as “Save Our Health Care” and “Corruption Is Not a Pre-existing Condition.” A representative from Planned Parenthood also spoke about Republican opposition to the nonprofit health organization.

U.S. Sen. Bernie Sanders, an independent from Vermont, called for similar rallies to take place around the country Sunday. Dozens were held.

The Republican-controlled Senate on Thursday passed a measure to take the first step toward dismantling the health care law.