<span>The answer is the Social Contract Theory. According to Thomas Hobbes, man originally lived in the state of nature. There was no government or any laws to regulate people. But there were hardships in society, so people came up with 2 agreements: Pactum Unionis and Pactum Subjectionis. The first pact allowed people to seek protection of their lives and belongings. This resulted in a society where people respected each other. The second pact let people united and pledge to obey an authority and surrender some aspects of their freedom to an authority. The authority granted protection of life, property, and liberty. So everyone had to agree to establish society by renouncing the rights they had against one another in the State of Nature and must have some person or persons with authority to enforce the social contract.</span>
<span>Europeans began to think differently about the world beyond their own. The age of exploration and discovery began.</span>
The steps that countries must take to transition to a mixed-market economy are: they must establish a fair labor market, and they must open up trade to other countries.
A mixed economy is an economic system which mixes elements of market economies with elements of planned economies. It's a mixture of public and private enterprise.
So, to have a country with a mixed-market economy, countries must establish fair labor market to have adequate conditions for the labor market. Moreover, they must open up trade to other international countries. That is to say, to have free trade which doesn't restrict exports or imports.
The Supreme Court and other federal courts (judicial branch) can declare laws or presidential actions unconstitutional, in a process known as judicial review. By passing amendments to the Constitution, Congress can effectively check the decisions of the Supreme Court.