It's manipulation. The RMB has been artificially fixed for decades for targetted economic/political reasons. It's being adjusted now not so that it can seek to a market value but to target another specific value for political/economic reasons. No one argues this. The PRC manipulates it's currency. It always has. It certainly doesn't seem likely to stop.

That said: this is what trade wars look like, folks. If we didn't want to fight in one we shouldn't have started it. The currency-manipulated status quo of the past two decades or so has lifted hundreds of millions of people out of poverty and made the world richer than it ever has been.

But no, someone's gotta score domestic political points based on a poor understanding of economics and some intuition about how to make a good populist argument.