The Trump administration’s pick to help overhaul the way many Americans finance their home purchases is expected to face questions about the future of the popular 30-year mortgage at his Senate confirmation hearing today, the Wall Street Journal reported. The Senate Banking Committee is considering the nomination of Mark Calabria to head the government’s oversight of Fannie Mae and Freddie Mac. The mortgage-finance companies guarantee roughly half of U.S. home loans and have been under government control since the financial crisis. If confirmed, Calabria would play a pivotal role as head of the Federal Housing Finance Agency in making changes to the companies. Calabria, a libertarian economist and senior aide to Vice President Mike Pence, is expected to face questions from lawmakers over his past calls for modifying the foundations of the U.S. mortgage market. While working at the libertarian think tank the Cato Institute from 2009 to 2017, Calabria advocated for curtailing government support for 30-year fixed-rate mortgages. These account for approximately 90 percent of new home loans, according to Mortgage Bankers Association data. He also called for banks to hold more of the loans they originate rather than selling them to Fannie, Freddie and other financing entities.