Conversation so far:
What political party is O'Reilly affiliated with?
CANNOTANSWER.
When did O'Reilly start his career as a political commentator?
CANNOTANSWER.
What stations did he work for?
Fox News.
What year did he work for Fox News?
dating back to 2002.
Is he still with Fox News?
On April 19, Fox News announced that O'Reilly would not be returning to the network.

Question: Did he have a successful career while at Fox News?
Self-contained rewrite: Did Bill O'Reilly have a successful career while at Fox News?