Did Schumer call Biden "the dumbest Senator"?

[unite for individuality]

Here's an excerpt from the speech Donald Trump gave Monday, September 21 in Vandalia Ohio:

(30:45 into speech)

   Long time ago, I had a friend, a senator, a Democrat, believe it or not.
   I used to get along with Democrats very well, actually better than the Republicans, but I won’t say that.

   But I asked him, “Who’s your smartest senator?” And he gave me a name. This is 25 years ago.
   I said, “Who’s your dumbest Senator?” “Joe.” “Who’s Joe?” “Joe Biden.” Oh, I see, he is, really?”
   â€œYeah, he’s the dumbest senator.” Well, now he’s a lot dumber than it used to be, I can tell you.
   It’s true. It’s true. It’s true.

https://www.rev.com/blog/transcripts/donald-trump-campaign-speech-transcript-vandalia-ohio-september-21

In this speech, Mr. Trump never identified the Democrat Senator who said this.
But...
The only U.S. Senator who ever appeared on The Apprentice is Charles Schumer.

[mountaineer]

It's really a tossup between Bob Casey and Joe Manchin, but Joe Biden is a contender for the title.

[jafo2010]

I saw Casey for the first time EVER the other day, getting questions from a reporter.  He is well known as the ghost of the Senate, for he is never there.

Manchin is considerably brighter than Biden.  Actually, I think there is a good chance he will vote in favor of Trump's judicial nominee.  West Virginia will NOT vote for him again if he opposes Trump on this issue.  He is intelligent enough to know this fact.