PORTLAND, Ore. -- U.S. Rep. Greg Walden (R-OR) has introduced a bill that would protect patients with pre-existing conditions from losing their health insurance, if the Affordable Care Act is repealed.

The bill would guarantee patients with pre-existing conditions would be able to get health insurance coverage through both the individual and group market. It would go into effect once the patient protections outlined in the Affordable Care Act, also known as "Obamacare," are repealed.

On the campaign trail, President Donald Trump promised to repeal the Affordable Care Act and replace it with a better alternative. Since he was inaugurated, Trump has begun the process of repealing the act through executive orders.

Without protections, as many as 18 million Americans could lose their health insurance if the Affordable Care Act is repealed.

Walden represents Oregon's second district and is the only Republican U.S. representative for the state. Following Trump's election, Walden was elected to serve as chairman of the House Energy and Commerce Committee, overseeing consumer protections, food and drug safety, public health and environmental quality, among other departments.