People who are against capital punishment argue that it violates

Eight Amendment

Explanation:

The death penalty is a very controversial subject in America. While many people support it, many others strongly oppose it. Those who oppose it often argue that it violates the Eight Amendment, which prohibits the federal government from imposing "excessive fines" or "cruel and unusual punishments" on criminal defendants.

there are indirect ways of affecting state laws   by with holding funding's. and that's why we have a 55mph speed on the high way with a design of 70mph speed.