We have term limits. Terms are limited when you vote incumbents out. Currently limiting terms does not happen because not enough people will vote for the other team to get a RINO out of office.
We also have true small government conservatives who run often enough. Taking Rand Paul as an example shows us something else, though. Paul ran against Trump the first time. People voting for Trump instead tells you the real probem isn't the politicians. The politicians are a reflection of the people. America's problem isn't elected officials. America's problem is America.