LOUISVILLE, Ky. (WHAS11) -- There's uncertainty about the future of the health care debate in Washington, DC. Recently the Vice President Mike Pence brought his pitch to Kentucky. Protesters brought their arguments too.

Many of those demonstrators rallied for single-payer, a system supported by Kentucky 3rd District Democrat US Congressman John Yarmuth.

Rep. Yarmuth has rallied for single-payer, which is often referred to as “Medicare for all.”

That system is on the opposite end of the spectrum of Affordable Care Act fixes backed by Republican US Senator Rand Paul who says he doesn’t want “another big government program.”

Some have asked, “What exactly is single-payer health care?” So, we looked to the University of Louisville and Doctor Elizabeth Munnich, an expert in healthcare economics.

“The economic models are easy to explain,” said Dr. Munnich. “What gets complicated is when you start merging them all together and bringing in politics and people and values and judgments and that's what makes it really difficult.”

Dr. Munnich does her best to tune out the political arguments and crunch data, studying the root costs and impacts of different systems of paying for health insurance and health care.

“Single-payer health care means that you have one insurance company, one payer, and that payer is the government,” Dr. Munnich said.

"In a single-payer model, the government would set the price and that would be the same for all consumers who are going to that hospital or seeing that doctor,” she added.

She said that several countries have single-payer systems. They're funded by tax dollars, although each system varies in what they fund with some offering additional insurance purchase options and others not funding prescription drug costs.

Single-payer remains off the table as the GOP considers its repeal and replacement options for the Affordable Care Act. It's unclear when the Senate may vote, with difficulties reaching an agreement now complicated by Wednesday's news that Senator John McCain was diagnosed with brain cancer.