The effect of a price floor on any good or service is not to increase the value of goods or services that are worth less than that price floor, but rather to make them worthless. By destroying the value of workers whose output would be worth less than $5.15/hour, the government reduces the supply of usable labor. This drives up wages for those who are fortune enough to be employed, while negating any wages for those who aren't. Even those who are employed, however, don't benefit much since increased wages lead to increased prices for goods and services, and the displacement of unskilled workers to the welfare office leads to higher taxes.
Free trade sounds nice and is sometimes necessary to break unions when they become to strong, but it is not without pitfalls. The fact is that people organize themselves into nations either to take advantage of other people or to protect themselves from being taken advantage of. If another nation manages to destroy your ability to get what you need, they can destroy your country and take what is yours.
The perfect example of this situation happened within our own country. The old South believed in free trade. They wanted to be able to buy British and French imports to their hearts' content without paying a tariff. The North wanted a tariff on British and French goods because that tariff helped manufacturers in the North who couldn't compete on either price or quality. Because the South believed that it could always get what it needed somewhere, it didn't develop a strong manufacturing base. In plotting a war to gain independence from the North, the South just assumed that the British and French would run the Northern blockades in order to have free trade with the South. What the South learned is that when the lead starts flying, the "principle" of free trade somehow loses its power to inspire people to action. Those who will yell the loudest to be able to trade without tariffs don't actually risk their lives for this idea. As a result, the North had more and better of every necessary supply throughout the war. While there are sometimes abuses in the name of "protectionism," a moderate amount is a good thing to ensure that we can always produce the things that we need in times of war or other troubles.
The other nice thing about tariffs is that they are the least intrusive form of taxation. Governments must raise money. An income tax is the most intrusive way to do so because it puts the tax man at the heart of our financial lives. A sales tax gives us a little distance, but the tax man is still watching every trade between fellow citizens. A tariff confines the tax man to the end of the dock. Maybe we can't raise all the money that we need through tariffs, but putting the tax man at the end of the dock as much as possible is a good thing.
WFTR
Bill