"I am not a crook!" quoting Nixon.
"Read my lips: no new taxes." quoting GHW Bush.
"Heck of a job, Brownie!" quoting Dubya.
/sarcasm, for those who are sarcasm-challenged.
Here's my real, non-sarcastic reply: IMHO, a Democratic candidate who wants to win actual points within his own party should never, ever quote a Republican, unless it's quoting their lies in context of exposing their lies.
"C'mon, man, you keep saying stuff like that and it never pans out. You've taught everybody what your word is good for."