It wasn't supposed to be this way.
When America's great think tanks were born, they were specifically intended to advance the public interest, the public welfare. That was before they were perverted to become a marketing/lobbying tool of the far right. From The New Republic.
The term “think tank” didn’t appear until the Kennedy administration, which relied heavily on Rand Corporation research, but these policy groups and research institutes date from 1916, when philanthropist Robert Brookings established the Institute for Government Research, which later became known as the Brookings Institution. Robert Brookings was one of a group of very wealthy businessmen who had become convinced that through the application of social science, government policies could be devised that would stem the rising conflict between the classes and parties and also achieve world peace. They were Theodore Roosevelt or Woodrow Wilson progressives in the broadest sense of the term.
Brookings wanted a research institute that was “free from any political or pecuniary interest.” The scholars didn’t raise their own money, but were employed like university faculty. In founding the Carnegie Endowment for International Peace, Andrew Carnegie went farther: In 1910, he endowed the new institution with bonds that he hoped would allow it to forego fundraising entirely. Other groups that began during those first decades included the Council on Foreign Relations, the Twentieth Century Fund (now the Century Foundation), the National Bureau of Economic Research, and the Committee for Economic Development.
The groups attained a reputation for intellectual independence. When coal company officials complained in 1933 to Brookings’ first president, classical economist Robert Moulton, about a study recommending their nationalization, Moulton responded, “We are concerned only in finding out what will promote the general welfare.” That reputation lasted into the 1960s, when, under John F. Kennedy, think tanks were conspicuously welcomed in the policy debate. But Robert Brookings’s early model of political disinterestedness and scientific objectivity began to erode soon afterward.
Three developments contributed to this change: Beginning in the 1940s, and in earnest in the early 1970s, conservative Republicans and business groups established think tanks and policy groups that had a specific economic and/or factional purpose. Businessmen dissatisfied with the New Deal created the American Enterprise Institute (AEI) in 1943. In 1964, it served as the policy arm of Barry Goldwater’s right-wing campaign for president, and in the ‘70s became the preferred think tank of the Fortune 500 and of center-right Republicans, even when, for appearance’s sake, AEI kept around a few liberal researchers.
Together, these business and conservative Republican groups attempted to take advantage of the reputation created by the older think tanks: They demanded attention for their “experts” in the media—on op-ed pages and, later, TV news shows—but they were in fact the kind of political organization or business lobbies that Robert Brookings and Andrew Carnegie had wanted to avoid at all costs. These groups’ scholarly output, particularly from a group like Heritage, was nugatory. They debased the coinage of the older thinking. And their model of partisan intervention and policy briefs spread leftward to groups like the Center for American Progress, which is something of a Democratic version of the Heritage Foundation.
Then there's the Canadian experience, the Fraser Institute. No matter how biased or outrageous the messaging of the Boys of Fraser, our media regularly pay them homage. For what? Because they exist on the payroll of some fairly narrow interests as their marketing/lobbying tool?
It's hardly any better in Britain where, save for Chatham House, the majority of think tanks are very much aligned, left or right.
The currency of think tanks, their credibility, has been severely debased. The majority are now mouthpieces for their patrons and ready to bend fact and truth to their supporters' service. And, for that, we're all worse off.