Tax collection is an important delegated power concurrent with both state and national power. Taxes are collected in various ways, such as the tax on certain foods and other items. Both state and national powers must apply and approve laws. If one body in the system does not enforce the law, the other will. Just like the legalization of marijuana, this is a controversial topic but sets a very important example in today's events. Since there are some states in the United States of America that have already legalized marijuana, national powers can overlook state laws and take federal action against those who break national law. The establishment of courts is an essential concurrent power needed by both state and national powers. Just as we need highways for the people and for the national powers. Highways are also designed to be convenient for both parties and to promote people's well-being. For example, the drinking age was once 18 and then states suddenly raised the drinking age to 21. This arrangement was made to protect younger children who were driving and drinking and to reduce the rate of deaths on highways. Of course the national powers had some sort of agreement with the state powers that the funds were still available. This specific mandate is called an unfunded mandate, one of Congress' strategies for influencing state policies (Barbour and Wright, 87-88). Even though the powers are said to be concurrent, there are always loopholes for what the national government wants from the state.