p>Advocates and progressive lawmakers on Sunday celebrated the 87th birthday of Social Security—one of the most popular and successful federal programs in U.S. history—and warned that its modest benefits remain under serious threat as Republicans openly signal their desire to gut the New Deal mainstay, a move that would hurl millions into poverty. For months, the Congressional Progressive Caucus (CPC) has been urging the Democratic leadership to bring a Social Security expansion bill to the floor, force GOP lawmakers onto the record, and advance a key legislative priority.