A House Democratic candidate said this week that Sen. John McCain, R-Ariz., has shown an amount of "courage" recently by standing up to President Trump, but lamented that this only happened after his brain cancer diagnosis.

"I’ve been tweeting on occasion about saluting Bob Corker and John McCain and Jeff Flake – men who have shown a little bit of courage speaking truth to their own party," said Dean Phillips, who is running for a House seat in Minnesota. "But it shouldn’t take brain cancer and the retirement from the Senate to do so.”

Phillips is running against Rep. Erik Paulsen, R-Minn., in the state's 3rd Congressional District. His comments came as McCain has continued to receive treatment for his brain cancer diagnosis in July.

A McCain spokesperson did not respond to a request for comment, and Phillips later apologized to McCain.

"First and foremost, I apologize to Sen. McCain for referencing his health, which I should not have done," Phillips said. "I greatly admire Sen. McCain's service to our country as well as his courage, and have for a long time."

"The point I was trying to make is that too many Republicans in Congress today — unlike Sen. McCain, Sen. [Susan] Collins and a few others — have shown a troubling lack of courage and willingness to stand up for their constituents, including when it comes to protecting their access to affordable healthcare."

"My sincere hope is that many more will join them in putting their country before their party," he added.

Phillips is the main Democrat running against Paulsen, a five-term Republican who has proven to be a difficult matchup for Democrats in recent campaign cycles. He won in 2016 by nearly 17 points over his Democratic opponent, but Democrats are hopeful that Phillips could be the candidate to defeat him.

Phillips, 48, has a lengthy business background, including having owned Talenti, a gelato company that was bought three years ago by Unilever.

Phillips is one of four Democrats vying for the seat, but is the favorite given his fundraising prowess. He has raised over $800,000, as of Sept. 30., the third quarter filing deadline. The primary election to face Paulsen is not until Aug. 18.

A year out from the election, Paulsen is favored to retain his seat as the University of Virginia's Center for Politics rates the seat as "lean Republican."