On Tuesday, just days after a bipartisan group of Senators released a set of principles to reform the immigration system with a pathway to citizenship for the nation’s 11 million undocumented residents, House Republicans convened a hearing to consider the benefits of immigration reform. The stacked witness list — of the eight witnesses testifying, four were opposed to comprehensive reform, and only one was clearly in favor — reflected the growing anxiety among conservative lawmakers about the cost of granting legal status to undocumented people, who, Republicans fear, would qualify for state or federal benefits and cost tax payers millions.