U.S. Sens. Bob Corker, R-Tenn., and Claire McCaskill, D-Mo., have introduced the Commitment to American Prosperity Act, which would phase in hard caps on government spending over a 10-year period and impose sequestration, or an automatic spending cut, if the caps were breached.

But in two new studies, Economic Policy Institute experts say the CAP act could severely harm both the social safety net which millions of Americans rely on, and the economy, especially during downturns like the Great Recession.

"Spending caps are much better rhetorically than they would be in practice," says Rebecca Thiess, policy analyst at EPI. "Rhetorically they sound very reasonable and responsible; [but] in practice they would decimate what government can spend on really important programs."