Sarbanes was his own campaign-finance guinea pig. The House weighs his bill Wednesday.

For years, Rep. John Sarbanes (D-Md.) had an ongoing experiment: testing his campaign-finance legislation on his own reelection races. He would set aside hundreds of thousands in high-dollar donations and would not touch it, not until he had raised at least $1,000 in small-dollar contributions from 100 different precincts in his district.