Sen. Marco RubioMarco RubioTop Trump officials push border wall as government shutdown looms Rubio defends Trump: 'This whole flip-flop thing is a political thing' Rubio: Shutdown would have 'catastrophic impact' on global affairs MORE (R-Fla.) on Tuesday criticized a Heritage Foundation study on the immigration reform legislation introduced in the Senate, calling the think tank's report "flawed."
The conservative think tank's study, released Monday, estimated that the immigration reform proposal would cost taxpayers $6.3 trillion over the next few decades. The Heritage Foundation says the immigration proposal offers amnesty to immigrants living in the country illegally.
A number of pro-immigration lawmakers and groups criticized the study. But Rubio, seen as a leader in the Republican Party on immigration, was noticeably silent on Monday.
Rubio also said that the study made some good points.
"We do want to address welfare benefits in the United States, the structure of the entitlement programs," Rubio continued. "But that’s not just true for immigrants; that’s true for everybody. ... I think the report, as much as anything else, is an argument for welfare reform and entitlement reform. Not necessarily an anti-illegal immigration reform study."
The Heritage Foundation released a statement Tuesday afternoon saying the think tank was still willing to work with Rubio.
"Heritage has worked with Sen. Rubio on numerous issues and we admire him. He is right: Our study is 'an argument for welfare reform and entitlement reform.' He cannot pretend, however, that this already herculean task will be made easier after we have added millions of new people to a failing entitlement system. The time to fix it is now. We are ready to work with him and any man and woman of either party who realizes the urgency of our plight."
Other members of the group of senators that introduced the immigration proposal also weighed in on the Heritage study. Sen. Jeff FlakeJeff FlakeTrump wall faces skepticism on border No Congress members along Mexico border support funding Trump's wall Obama-linked group launches ads targeting Republicans on immigration MORE (R-Ariz.) said the study completely ignored the "economic benefits" of the immigration proposal.
"New Heritage study claims huge cost for Immigration Reform," Flake wrote on his Twitter account. "Ignores economic benefits. No dynamic scoring."
Later Tuesday, Rubio met privately with conservative groups and think tanks in his Senate office to hear out their concerns about the immigration bill.
Attendees at the meeting included representatives from the American Enterprise Institute, the Manhattan Institute, the Leadership Institute, the Council on Foreign Relations, and the CATO Institute. Representatives from other conservative organizations were on hand as well, including the American Action Network, Americans for Tax Reform, Tea Party.Net, and American Crossroads.
Grover Norquist, president of Americans for Tax Reform, said border security was a big topic at the meeting.
"Here's what came up that we kept hearing: ‘We don't believe that the this administration will enforce any of the rules you have for tougher border security,’” Norquist said.
Here's the full list of attendees at the Rubio event, according to a person who attended:
Al Cardenas, American Conservative Union
Sal Russo of Tea Party.Net
Diana Furchtgott-Roth of the Manhattan Institute
Ken Weinstein, Hudson Institute
Alex Nowrasteh, CATO Institute
Barrett Duke, Southern Baptist Convention
Morton Blackwell, The Leadership Institute
Niger Innis, Tea Party.Net
Todd Cefaratti, Tea Party.Net
Grover Norquist, ATR
James Pethokoukis, American Enterprise Institute
Elliott Abrams, Council on Foreign Relations
Paul Wolfowitz, American Enterprise Institute
Steven Law, American Crossroads
Douglas Holtz-Eakin, American Action Network
Norm Coleman, American Action Network
John Shadegg, who is a Visiting Distinguished Fellow at the Heritage Foundation.