Eric Cantor: GOP and Trump 'will sink or swim together' on health care

"This is Donald Trump's party now." Cantor said.

“At this point, Trump is the quarterback of the team,” Cantor told ABC News' Jonathan Karl on the “Powerhouse Politics” podcast. “He is the one that is ultimately calling the shots and will ultimately make the difference for the Republican members in terms of their political viability and [potential to be re-elected]."

To any who may expect conflict brewing between Trump and Ryan over health care, Cantor says the president and House speaker will stay on the same page for practical reasons.

“This will be a unified front in the end, Cantor said. They will sink or swim together. There's no option to fail here.”

With Republicans in control of both houses of Congress and the executive branch, “there’s no excuses in the eyes of the American voter” for the health care bill to fail, Cantor said. “It has to get done,” he said.

“This is a gateway issue … It’s that important because it opens up the route toward getting the next big thing done, which is tax reform,” Cantor told ABC News.

"If there's any indication that some of this is not going to happen, I think there will be negative impact on the markets," Cantor said, reiterating that Congress must work with Trump to get these two major GOP agenda items across the finish line.

ABC News' Adam Kelsey contributed to this report.