STEVE INSKEEP, HOST:
In this country, 2016 is developing into really interesting political year, entirely aside from the presidential race. Consider a congressional district in Maryland where there is an open seat. It is a deep blue district, which means the game is to win today's Democratic primary. It's become the most expensive House primary in America. Here's Patrick Madden of our member station, WAMU.
PATRICK MADDEN, BYLINE: For many who call Montgomery County, Maryland home, politics is more than a hobby. It's a livelihood.
KATHLEEN MATTHEWS: This is a unique congressional district. It's in the shadow of the capital.
MADDEN: Kathleen Matthews is a former TV anchor and Marriott executive and one of the frontrunners in this race.
MATTHEWS: It also has more people with advanced degrees than any other congressional district in the country, I'm told.
MADDEN: So when the local congressman decided to run for Senate, a whole gaggle of well-known and well-funded candidates jumped into the race. The fight to win the Democratic nomination here has quickly become the most expensive House race in the country, approaching $20 million.
All that spending comes even as the candidates in this liberal district all denounce the influence of money in politics. Most of the money comes from this guy.
(SOUNDBITE OF POLITICAL AD)
DAVID TRONE: Politicians talk about creating jobs. But I've actually done it.
MADDEN: David Trone is a wealthy businessman who has put at least $12 million of his own money into the race. Like another famous wealthy candidate, Donald Trump, Trone says his fortune lets him stay independent of campaign donors.
TRONE: The fact that I'm spending my own money, that's a testament that I want to make a difference. I want to make something change.
MADDEN: The race had been shaping up as a two-way battle between former television anchor Kathleen Matthews and state Senator Jamie Raskin, says Jonathan Shurberg. He writes the Maryland Scramble blog and is one of the most plugged-in analysts of Maryland Democratic politics. That is, Shurberg says, until Trone stepped into the race at the last minute.
JONATHAN SHURBERG: Whatever movie script people were playing out, he's like Godzilla. He's come in from a different movie and is just stomping on all the scenery.
MADDEN: And if you've been anywhere near a TV in the very expensive Washington, D.C. media market, you can't avoid Trone's ads.
SHURBERG: My joke has been sort of, you know, you can run but you can't hide.
MADDEN: Trone's opponents have tried to make an issue of his spending. Kathleen Matthews accused Trone, who made his fortune building a chain of beer and wine stores, of using his money to buy a seat in Congress, quote, "as if it's a fine wine."
But Trone's big spending has forced others to catch up. Matthews later loaned her campaign half a million dollars to keep pace. Even Trone admits that campaign spending from everyone has gotten out of hand.
TRONE: It's absolutely too much money. We need public financing of campaigns.
MADDEN: Trone defended himself with an open letter to voters that criticized his opponents and the media for focusing on his spending. To get the message out, he bought a pricey full-page ad in The Washington Post. For NPR News, I'm Patrick Madden. Transcript provided by NPR, Copyright NPR.