From a libertarian perspective, they are a bad option for consumers' choice. If the government raises tax prices on imports in order to compel another country's compliance, the country may not comply anyway, so the tariff only has the effect of raising costs for vendors that sell them in the United States and raising prices for consumers. If one values free market trade in a globalized international market, then the consumers lose out because their choices are more restricted than before. They may have really preferred paying low prices for Chinese manufactured goods despite whatever political problems China may be causing for the United States government. Now with new tariffs, they have to pay artificial higher prices for those same goods, or they have to buy an American made or other country made product that for a wide range of reasons they may not want. If anyone is interested, read Capitalism and Freedom by Milton Friedman, and pay special attention to the chapter on import tariffs.
Trump and many of his supporters believe that tariffs will compel other nations to do what the United States government wants, and that domestic United States based companies will purchase cheaper alternatives for production and sales in the United States. This would have the effect of hypothetically bringing back U.S. manufacturing and services jobs which had been largely phased out due to decades of international manufacturing outsourcing. The intended effects of these actions are to increase wages for U.S. workers and to create tens of thousands of new well-paid U.S. jobs. This would come with a store price finished goods result of either new prices low enough to be comparable to low-cost Chinese goods or prices that are slightly higher but would not be as big of a blow to the average consumer's wallet because the consumer would have higher wages.
In theory, it's supposed to bring back jobs, but tariffs have to many unintended consequences like trade wars and again reducing consumer choice. The left keeps repeating that the tariffs will in fact raise prices for consumers by a large margin, while conveniently leaving out their intended effects of raising domestic manufacturing and creating higher paying jobs, which then would stabilize prices anyway.
My take is Friedman's, in that the consumer is really the one that is taking a blow to his or her purchasing liberties here and that tariffs are just another way of an over-reaching government limiting its citizens choices. That's just my take, but I'm more than willing to change my opinion based on new information.
One more thing. It is certainly the case that U.S. consumers purchase lower prices due to the Chinese government's lack of worker's rights and fair wages. If you look at the history of national industrialization, these are growing pains that occur in every country. The workers have already seen improvements in conditions and pay over the last two decades, though much more human rights work needs to be done. Studies have indicated that millions of Chinese manufacturing workers prefer the drudgery of factory work over the much worse drudgery and health problems working on Chinese farms. The future will see Chinese workers continue to fight for fair wages and better working conditions while being aided by human rights organizations which did not exist a century ago.