Rush Limbaugh: Entertainer or GOP’s guru?

Rush Limbaugh has been an officially appreciated voice of the Republican party (or GOP, or conservatism–pick your poison) for over 17 years. This from wikipedia:

A month after Bill Clinton‘s defeat of George H.W. Bush in 1992, Ronald Reagan sent Limbaugh a letter in which he thanked him “for all you’re doing to promote Republican and conservative principles… [and] you have become the Number One voice for conservatism in our Country.”[137]