As you've learned, the Senate has undergone a radical transformation in the way its members are selected. For the first 130 years, senators were appointed by their respective state legislatures.

Changing the Rules

The selection process was troubled from the beginning, rife with inconsistencies, corruption, backroom deal-making, and ultimately, mistrust from the public. Starting with Oregon in 1907, states began scrapping the selection process and replacing it with direct elections. Sensing that the tide had turned, the Congress followed suit. The Seventeenth Amendment to the Constitution, which changed the process of selecting senators, was ratified in 1917. The amendment did not, however, alter the formal qualifications established in the Constitution for becoming a member. Senators still must be thirty years of age or older and a United States citizen for nine years prior to election, and they must be residents of the state they represent.

Money, Money, Money

Although anyone who meets the age, citizenship, and residency requirements can run for the United States Senate, the most important requirement is money — and lots of it. The average senatorial candidate spends $5 million during each campaign in hopes of achieving victory.

Over the past decade, there has been a surge in the number of wealthy individuals who have sought Senate seats, and approximately one-third of the chamber is now composed of millionaires. Outside of the superwealthy who can finance their own campaigns, most members spend anywhere from a quarter to a third of their time raising money for re-election. Members and challengers from states like California, New York, and Texas, where media is expensive, can spend upward of $25 million to win or retain a seat — a truly staggering sum of money.