A couple of decades or more ago when I was still in Washington, otherwise known as the snake pit, I was contacted by a well-financed group that offered me, a Business Week and Scripps Howard News Service columnist with access as a former editor also to the Wall Street Journal, substantial payments to promote agendas that the lobbyists paying the bills wanted promoted. 

To the detriment of my net worth, but to the preservation of my reputation, I declined. Shortly thereafter a conservative columnist, a black man if memory serves, was outed for writing newspaper columns for pay for a lobby group.

I often wondered if he was set up in order to get rid of him and whether the enticement I received was intended to shut me down, or whether journalists had become "have pen will travel"? (Have Gun—Will Travel was a highly successful TV Series 1957-1963).

Having read Bryan MacDonald's article on Information Clearing House, "Anti-Russia Think Tanks in US: Who Funds them?," I see that think tanks are essentially lobby groups for their donors.