The system of checks and balances is a way to keep any branch of government becoming too powerful. For example, congress passes bills into laws, but the president can be able to veto the bill. However, if the congress can get two-thirds majority vote, they will be able to overrule the veto. Also, congress is able to strike down any law that violates the constitution saying it is unconstitutional. In the end, the Constitution balances power among the three branches of government.