What does "check someone for power" mean?

1.a system that allows each branch of a government to amend or veto acts of another branch so as to prevent any one branch from exerting too much power.

Definition of in someone's power

1: in a position of being controlled by someone other than oneself

She had them in her power.

2: able to be done by someone: within one's ability

It's in your power to change the way things are done here.

I'll do everything in my power to help.

Explanation:

they wanted the u.s. to fight on the side of the central powers.

the virginia plan called for three branches of government and two houses of congress. representation in each house would be determined by population. the new jersey plan called for three branches of government and a single house of congress. each state would have an equal vote.