Politicians are falling all over themselves to figure out Snapchat and Instagram, but Donald Trump learned the hard way that a supposedly dying medium still has the power to break a candidacy.

Pundits have plenty of theories on why Trump lost last week's Wisconsin primary to Ted Cruz. Some said Wisconsin voters are just too nice to embrace Trump's bombastic behavior. Others argued that Trump's critique of Wisconsin Governor Scott Walker, a popular figure among conservatives in the state, gave Cruz a boost. But one of the prevailing theories explaining the loss was the idea that a vocal group of local anti-Trump radio hosts are what really crippled Trump's campaign.

Yes, that's right. Radio hosts.

It's been 35 years since "Video Killed the Radio Star." It's been 16 years since Pandora launched, driving yet another symbolic nail into radio's coffin. At this point, most of us have quit debating whether the radio industry is dying. For lots of listeners, it's already six feet under.

And yet, even as radio has struggled in the internet age, as competing technologies like streaming and social media consume an ever growing share of public attention, conservative talk radio has managed to survive, and in some cases, even thrive, becoming powerful enough to make or break even the most formidable frontrunners.

Chart-Toppers

Just take a look at TALKERS magazine's list of the top talk radio shows this month. Four of the top five are conservative commentators, including Rush Limbaugh, perpetual chart topper; and Sean Hannity just below him. At the annual Conservative Political Action Conference, where crowds gather just to watch their favorite conservative hosts talk to a live mic, Hannity is a rock star.

Rarely, however, is the political influence of conservative radio as strongly felt as it is during presidential primary season. That's because the people who are most likely to vote in a Republican primary and the people who are most likely to listen to talk radio are essentially the same. As a rule, Republican primary voters tend to be predominantly male, white, and over the age of 45. The same goes for talk radio.

Meanwhile, other studies have found that people who consistently vote conservative, making them more likely to be primary voters, are also more likely to list local radio as one of their top media sources.

All of which is to say that talk radio hosts are, generally, preaching to the choir, and in a primary season, that's a very powerful thing.

It was especially powerful in Wisconsin, given that the six most popular conservative hosts all happen to be anti-Trump. That has not been the case throughout the talk radio landscape this election cycle. While better-known hosts like Limbaugh and Hannity haven't explicitly endorsed Trump, they haven't rejected him either. On TV or radio, Trump is always great for ratings.

But the Wisconsin hosts broke from that mold. And it appears to have worked.

"They have an audience that trusts them, and that leads to influence," says Matt Lira, a Republican digital strategist and senior adviser to House Majority Leader Kevin McCarthy.

A Sign of the Times

Conservative talk radio started as a product of the times. Throughout much of radio's history, the Federal Communications Commission's so-called Fairness Doctrine required broadcast media outlets to present contrasting arguments on controversial topics.