The most significant revision of U.S. immigration laws in a generation will come under a new line of attack for its potential costs to public programs including Social Security and Medicare.

Jim DeMint, a former Republican senator from South Carolina and now president of the Washington-based Heritage Foundation, will lead the assault with a report from his Republican-leaning institute as early as next week on the costs government would bear in offering a path to citizenship for 11 million undocumented immigrants already in the U.S.

As the Senate Judiciary Committee starts weighing the immigration bill next week, the argument over costs -- which helped sideline the last attempt at an immigration revision in 2007 -- will join Republican opposition to citizenship for the undocumented and demands for sealing the nation’s borders as factors that could prevent Congress from acting again this year.