Since the birth of his son Billy in 2017, Jimmy Kimmel has been outspoken about the importance of insuring those with preexisting medical conditions.

Billy Kimmel was born with congenital heart defects and has already undergone three surgical procedures.

In a video posted Thursday to his show's YouTube page, the "Jimmy Kimmel Live!" host shared photos and video of Billy through the years and made an impassioned plea for Americans to vote in the upcoming presidential election.

Kimmel, a longtime critic of President Donald Trump, slammed Republicans for what he said was an effort on behalf of the party to gut coverage of those who have preexisting conditions.

"The vast majority of this country agrees that health insurance should cover Americans with preexisting conditions," he said, noting that it's "not a partisan issue."

"My wife made a video that deals with our experience when it comes to preexisting conditions," he added. "We'd like you to watch it and pass it around to anyone who may have forgotten what this election is really about."

In Thursday night's debate between Trump and former Vice President Joe Biden, both candidates delivered pitches regarding health care -- the issue 2018 voters rated as the most important.

Trump boasted of his administration's effort to roll back the Affordable Care Act's individual insurance mandate, calling the entire act "no good." However, he did pledge to protect its popular coverage guarantees for those who have preexisting conditions. Trump also falsely accused Biden of wanting to eliminate private insurance and tried to link him to the universal, single-payer proposals offered by other Democrats. Biden said that his plan maintains private insurance and builds upon the ACA by offering a public health care option.

"It'll become Bidencare," Biden said. "Not one single person with private insurance would lose their insurance under my plan."

Trump spent much of the 2016 campaign stating he would "repeal and replace" Obamacare, but the repeal has fallen flat and a potential replacement failed in the Senate. The president has also spent much of his tenure in the White House pledging a new health care plan, but has yet to offer concrete details.

Meanwhile, the Trump administration has called on the U.S. Supreme Court to completely strike down the ACA; justices are expected to hear oral arguments in the coming weeks. If it is struck down, some 20 million people who rely on the ACA could be left without insurance during a global pandemic.