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

— -- The new GOP health care proposal may have taken on the moniker “Ryancare” after House Speaker Paul Ryan, but former House Majority Leader Eric Cantor says at the end of the day it all belongs to Trump.

“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]."

For the sake of Trump’s credibility and ability to move the rest of his agenda, the GOP health care proposal needs to get passed by Congress, Cantor said.

“It can’t go down,” said Cantor, who represented a north-central Virginia district in Congress for over 13 years before losing in the 2014 GOP primary to now-Rep. Dave Brat. “That’s just the bottom line.”

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.

Cantor said that if the GOP cannot get health care reform passed, that could be a death knell for other items at the top of Trump’s agenda.

“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.

Cantor is now vice chairman of Moelis & Company investment bank and advises companies around the world on how to position themselves in the global marketplace. He said that even though the issue of corporate tax reform has divided the business community, it, along with changes to health care policy, are critical for U.S. economic stability.

"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.

"At the end of the day, this is Donald Trump's party now."

ABC News' Adam Kelsey contributed to this report.