What were two checks on power in the Roman Republic?

I'm not pretty sure if this is what you wanted

What made this system interesting is that there were two Consuls at any given time, and bothcould veto each other. Giving this executive, the Consul, the power of veto is another addition into Roman checks and balances put in place to keep one man from ruling all of Rome, which is why there was never a Roman Empero

this is a good question! i'll do some research and come back when i have the answer!

necessary and proper clause. the congress shall have power to all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states, or in any department or officer thereof.