Because he thinks it makes him look cool and edgy, especially in an environment like this, where the way to gain popularity is to be the most extreme far left voice in the crowd.
People like that are the vegans of politics: even if you may agree with them in many ways, their repulsive attitude and conduct more than overrules any common views you might share.
Anyone who thinks tariffs will do anything at all positive for the American working class is absolutely clueless.
All they do is make prices jump for consumers. It doesn’t put domestic goods at an advantage because the domestic producers of those goods increase their prices artificially to achieve parity with import pricing.
So prices go up for the consumer with the extra money going to either:
or