VISTA, Calif. – Dozens of demonstrators rallied outside Rep. Darrell Issa’s Vista office Tuesday to protest a Republican bill that would repeal the Affordable Care Act.

House Republicans introduced their bill Monday to repeal Obamacare’s individual mandate. It would, however, maintain coverage for people with pre-existing conditions and allow children to stay on their parents’ plans until the age of 26.

The measure would offer individuals refundable tax credits to purchase health insurance and restructure the country’s Medicaid program so that states receive a set amount of money from the federal government every year — changes experts warn could result in millions of people losing access to insurance they received under the Affordable Care Act.

It also largely would keep Obamacare’s protections of those with pre-existing conditions, but allows insurers to charge higher premiums to those who let their coverage lapse.

The measure sets up a political battle that could consume Congress for much of the year.

Protesters in San Diego say they are rallying for people who will be harmed by the bill.

“We know that millions of people will be affected by the ACA repeal,” organizers said in a press release. “But what’s new is the massive cuts proposed to Medicaid, which affects not only people with lower incomes, but also people with disabilities–adults and children alike.”

Trump critics have been holding weekly protests in front of Issa’s office. Tuesday’s rally is expected to begin around 10 a.m.

Check back for new information on this developing story.