Conversation so far:
was Jerry in politics?
It continued while he was still mayor of Cincinnati.
How long was he Mayor?
CANNOTANSWER.
Was Jerry a journalist?
Springer was hired as a political reporter and commentator.
Who did he work for?
on Cincinnati's NBC affiliate, WLWT.
Did he work for any other networks?
In 1997, the Chicago-based NBC-owned station WMAQ-TV hired Springer to serve as a news commentator.
How long was he a journalist?
CANNOTANSWER.
Any other interesting facts about this article?
With the help of some others at WLWT, he created his signature line.

Question: What was his signature line?
Self-contained rewrite: What was Jerry's signature line?