First, we have an old Senate hand, the 76-year-old Thad Cochran. He's GOP establishment, I suppose, so the Tea Partiers want to pick him off and install one of their own. I don't know anything about Cochran's record or whether he's still a political force. He's certainly not one of the big names in the Senate. The biggest news story I read about him was that he doesn't know much about the Tea Party. That strikes me as strange, especially since he's in the politics business. Maybe he's getting a little out of touch or senile, or maybe there's some other explanation (like he focuses on other more important issues).
His opponent, Chris McDaniel, 41, wants to be another Tea Party superstar like Ted Cruz. (My opinion of Ted Cruz is that he's all flash and no serious thought, so we definitely don't need another of that kind.) Unfortunately for McDaniel, a rabid Tea Party supporter filmed Cochran's senile wife in her nursing home, which is not only in bad taste but also against the law. The supporter and several others have been arrested and charged.
It probably should have been easy to defeat Cochran... unless you ended up looking more unsavory than him. That's what this supporter managed to do. It was emblematic of the Tea Party's desire to unseat all RINOs by any means possible, and it showed how they'll cross the line without a second thought. In the primary, the Tea Party challenger didn't win an outright majority and now has to compete in a runoff with Cochran (probably, not definitely). This looked like it should have been a win for the Tea Party, and that supporter blew it. What an amazing self-inflicted wound.