In the United States, constitutional restrictions hinder the effective operation of government by making it harder for the government to take any actions. The Constitution was written in such a way as to make it difficult for the government to do anything. This hampers governmental efficiency.
To understand this, let us look at our current situation. We have serious problems with government deficits and the government is unable to agree on a solution. Because of the Constitution, any solution would need to pass both houses of Congress and be signed by the President. However, the House of Representatives and the Senate are controlled by different political parties. The President is a Democrat and the Senate has a Democratic majority, but the House is controlled by the Republicans. This has made it exceedingly difficult to get anything done. The two sides find it impossible to agree with one another on serious solutions. Because of the way the government is set up, it cannot efficiently institute policies that would solve the debt issue.
The Constitution was set up to make it harder for the government to do anything. The restrictions that were applied for this purpose make efficiency very difficult.