WASHINGTON — With his passion for history, Richard Nixon undoubtedly would have appreciated the irony.

On the last day of the former President's life, Hillary Rodham Clinton sat in the State Dining Room at the White House, fielding the most intimate and pointed questions any First Lady had ever faced from reporters. Twenty years ago, she had come to Washington as a young law school graduate to work on the House Judiciary Committee's impeachment proceedings against Nixon. Now she was dodging rocks from the landslide that those proceedings, and the Watergate scandal that precipitated them, had set off in U.S. politics.

Many events in Nixon's rise affected the climate of contemporary politics--from his trumpeting of the Silent Majority, the distant predecessor of Clinton's forgotten middle class, to his elevation of crime, civil rights and other "wedge" issues that split the New Deal Democratic coalition along racial and class lines. But nothing Nixon did influenced American politics more than the manner of his fall.

As much as any other single event, Watergate has shaped the rules and rhythms of modern political life. The scandal that destroyed Nixon's presidency stands as a transitional event--from an insular, clubby and even secretive political process to a system that is more open and decentralized but chaotic, cynical and vitriolic.

Watergate changed the way the public and the press view politicians; it influenced the way candidates raise money, the way Congress conducts its business and the level of disclosure about private lives that is demanded of public figures, such as Hillary Clinton.

Perhaps most directly, it institutionalized the use of scandal as a weapon in the ongoing ideological and partisan wars over policy. After Nixon's fall, the pursuit and promotion of scandal has become a routine tool that political parties use to weaken their opponents and derail their policy agenda. From Jimmy Carter's Peanutgate (the probe of whether peanut warehouse funds were diverted to campaign coffers) to Whitewater, every President since Nixon has been confronted with at least one major scandal that threatened to erode his political support.

"It was in a sense the founding of this new form of politics," said Cornell University professor of government Martin Shefter, co-author of "Politics by Other Means," a book examining the role of scandal in the struggle between the parties.