O'Reilly spent years as the "network announcer" the utility infielder of the business, so he knows the drill.
He is also a complete fake. He is the Designated Democrat Operative, whose role is to keep the dwindling number of "Blue-Collar Working Class Catholics" left in the country* within the Democrat Party fold. He is a reach-out to the Daily News reader of the 1950s.
O'Reilly is first and foremost, a highly partisan Democrat who has never, that's NEVA, endorsed a Republican Candidate for anything, much less voted for one. If Jesus Christ were running for Mayor of NYC on the Republican ticket, and Lucifer as the Democrat, O'Reilly would vote for Satan. Twice.
*Many Catholics, especially the older ones, still believe they are voting for Harry s. Truman and that one can be a patriot and a Democrat at the same time. BTW, the Democrat Left Wing Leadership openly despises them .... and O'Reilly.
I can't recall him ever endorsing anyone, R or D.