We got the New York Senator at Capitol Hill Wednesday and asked about China's Twitter ban ... he says the policy's a good thing -- at least while the Prez is there. As for China as a whole ... Schumer's clearly not a fan.

The joke's on Chuck, though ... because Trump's still tweeting away, reportedly with the help of special equipment that lets him bypass the country's Internet firewall.

Right around the time we talked to Schumer, Trump posted a reminder of last year's election victory.