He didn’t create bigotry. He helped create the atmosphere where being deliberately insensitive to others’ problems was considered legitimate political expression. This behavior was previously considered “just being an asshole.”
Helped create? Maybe I' could almost by that. I am tempted to say that Westbrook Pegler originated it with his attacks on "bleeding heart liberals". From what I can gather; he helped foster "Archie Bunker" blue collar conservatives that became the current America First crowd. That is Trump's base.
As you likely know, there are two main streams of conservatism. One, the aforementioned America Firsters. They are populist, neomercantilist, nativist-nationalist, xenophobic ... The other is intellectual, globalist. pro-free trade. Both tend to favor low taxes, small government, private property, and free markets.
They held together since Buckley banished the JBS through the Reagan-Bush years, largely by a common strong opposition to the Soviet Union. Anyway, after the demise of the Soviet Union, it became increasingly difficult to hold the two together.
Limbaugh, like Reagan, captured the support of both, at least early on. I gather, the "deliberately insensitive to others’ problems" is a reaction to the 'irreverent satire'; most of which panned and parodied the sacred cows of the left? That was a lot of Rush's appeal. In the context of 1988, he was shockingly and outrageously funny. And nuanced at the same time. He loved the women's movement; especially when he was walking behind it. This in contrast with Morton Downey Jr., who was just mean and angry at the "pablum puking liberals."
I had quit listening by the time W became President -- too many other things going on. Plus, Limbaugh's satire had gotten stale at best. So I can't really comment on what I didn't hear. I tuned in a little the last 5 years, was disappointed Rush had sold out completely to Trump, even saying at one point. that nationalism trumped conservatism. (In the past, he backed Republicans and NAFTA against Perot). Also said Biden's victory was arranged.