Flake is a member of a bipartisan group of senators that unveiled an immigration reform proposal earlier in the year. On Monday, Heritage released a study estimating the legislation would cost taxpayers $6.3 trillion over the next few decades.


"No matter how you slice it, amnesty will add a tremendous amount of pressure on America's already strained public purse," Robert Rector, a senior research fellow in domestic policy studies at Heritage, said.

Both Flake's tweet and the Heritage study comes the same week the Senate Judiciary Committee will markup the 844-page immigration bill.