Why is the U.S. tough with Thailand, but not China?

From Thairath, September 30, 2105
Chai Rachawat, 28 September 2015
Left, Thai man: Why is America pressuring us [Thailand] to arrange a proper election, unlike how you do with China. China never has a proper election. Why you stay silent with the China?
Middle, Uncle Sam: That’s because China knows how to close our mouths.
Thai man: What did China do?
Right, Uncle Sam: They ordered 300 of our Boeing planes to shut our mouths!