What's the CBO? Meet the nonpartisan agency under fire from Republicans.

The Congressional Budget Act of 1974 established the Congressional Budget Office, an agency designed to provide lawmakers with objective information about the budgetary impacts of proposed bills. Up until that point, the scorekeeping within the government came from the executive branch.

Top Republicans, including President Trump, are criticizing the nonpartisan Congressional Budget Office over its assessment that GOP's signature policy bill could add $2.4 trillion to the deficit.

(Image credit: Visual Generation)