Their lack of success may be attributed to the difficulty of amending the Constitution.
Nolan said "painstaking" as the process can be, he's up for the challenge.
"It wouldn't surprise me if this took five or even 10 years," Nolan said. "But there is no doubt in my mind that the movement to amend will ultimately be successful."
To alter the Constitution, an amendment has to be proposed either by a two-thirds vote in both Houses of Congress, or by a constitutional convention.
The amendment then has to be ratified either by the legislatures of three-fourths of the states, or by conventions in the same number of states, depending on which means of ratification Congress proposes.
A convention, however, is highly unlikely. It was only resorted to once, for ratifying the 21st Amendment to the Constitution, which eliminated Prohibition. All other constitutional amendments were proposed by Congress.