The Senate is a brake on change. In the most egregious example, the House passed anti-lynching legislation for 50 years, which never made it out of Senate committee.
Patriot act was ultimately designed to avoid the types of failures to coordinate that stopped the authorities from preventing 9/11 attacks. It was very successful at that aim, but created a bunch of other problems in the process. My statement isn’t an endorsement of it.
ACA reduced the number of uninsured individuals by 50%, eliminated a few key policy holes (ie pre-existing conditions) and slowed cost growth.