RICHARD M. Nixon was a strong and capable president who might have gone down in history as one of the most effective. Instead, he will be remembered for undermining the presidency and reducing the respect Americans have for their institutions.

In 1968, candidate Nixon took as his running mate Gov. Spiro Agnew of Maryland, whom he later came to belittle. He toyed with replacing Vice President Agnew with someone of greater stature in 1972, but did not.

Democrats, writing off the presidential election of 1972 as unwinnable, nominated Sen. George S. McGovern of South Dakota, who was true to the ideals of their left wing but hardly presidential to the broad center of the electorate.

The failed burglary of the Democratic National Committee in the Watergate on June 17, 1972, and its clear links to the Nixon campaign became a live issue. The Democrats would have won the election with a more substantial nominee.

The voters overlooked Nixon's misdeeds, as in 1992 and 1996 they would ignore allegations about Bill Clinton, because they rejected the alternative.

Political implications

But there was a Democratic Congress to face in 1973 that understood the criminality in Watergate and hoped to tie it to Nixon and nullify the election.

Investigations by the Justice Department showed the burglary to be part of a pattern of presidential misbehavior, which led to the House investigation in which Rep. Paul S. Sarbanes of Baltimore played a prominent role.

Meanwhile, an unrelated investigation by the Republican U.S. attorney for Maryland into corruption in Baltimore County's Democratic administration collided with these great events.

The dragnet through the Towson court house netted evidence against an unintended target, the former Republican county executive, Spiro Agnew. A contractor recounted payoffs that continued through Agnew's governorship and into his vice presidency.

Agnew's plans

As early as May 1973, Nixon wondered to a confidante whether he should resign. Agnew could picture himself becoming president, possibly immune to the case gathering against him. Attorney General Elliot Richardson foresaw the possibility and was determined to prevent it.

On Oct. 10, 1973, Agnew stood in the federal court house on Calvert Street, now Court House East of Baltimore Circuit Court. There he pleaded no contest to one count of tax evasion, and announced his resignation from the vice presidency. It was the most celebrated plea bargain in history.

The 25th Amendment to the Constitution, which provides for replacing the vice president in such a circumstance, had been ratified only six years earlier. It was untested, not a hallowed part of the American way.

Under its terms, Nixon nominated House Minority Leader Gerald R. Ford to be vice president. Mr. Ford was easily confirmed by simple majorities of the House and Senate. He was hardly the largest political figure available but he was the Republican most easily confirmable in Congress, which looks kindly on its own.

When sufficient Republican voices joined the Watergate chorus, making impeachment certain and conviction probable, Nixon resigned his office on Aug. 8, 1974, effective Aug. 9.

The 25th anniversary of that event was widely remembered this week, mostly without noting its lasting dismal effect on the nation.

A banana republic

Mr. Ford became president without having been elected by the people to anything more than to represent the Third District of Michigan. The United States was suddenly a banana republic, its president replaced by a bloodless coup.

Mr. Ford was thought to be a dull conservative, decent but none too bright. Not since states seceded in 1861 rather than accept Abraham Lincoln as president had the institutions established by the Constitution been so fragile. Nothing seemed durable.

Mr. Ford went on to perform the greatest service to the republic of any recent president. He restored public trust in the integrity of national institutions.

His controversial pardon of Nixon, preventing the possibility of criminal proceedings, began the national healing process while dooming Mr. Ford's own 1976 election bid. For him, the nation came above ambition.

But even Mr. Ford could not bring confidence all the way back. Since then, Americans have not taken it for granted that a four-year term is just that.

Congress institutionalized the office of independent counsel, which was then used to damage, harass or try to bring down presidents, starting with Jimmy Carter.

Impeachable offenses

Nixon was the only president in U.S. history who committed high crimes and misdemeanors against the constitutional process such as the Framers of the Constitution imagined as grounds for impeachment and removal.

Most past presidents for whom impeachment was suggested or attempted were, rather, engaged in great policy struggles with a Congress of the other party. This describes Presidents Andrew Jackson, John Tyler, Andrew Johnson and Ronald Reagan.

Jackson was censured by the Senate. Tyler was nearly impeached. Johnson was impeached in 1868 and escaped conviction by one vote. Mr. Reagan was hounded by an independent counsel investigating shadowy dealings that violated congressional micromanagement of foreign affairs.

The misdeeds of President Clinton were not even in that league. The independent counsel helped to trap Mr. Clinton into giving dishonest testimony in a dubious civil lawsuit, and obtained his impeachment for that. This nearly worked. Half the senators voted to remove him from office.

It was political payback for what had been done to Nixon and attempted against Mr. Reagan.

A do-nothing Congress

Now the office of independent counsel is in disrepute. The law establishing it was allowed to lapse by a Congress that solves problems through inaction. The beauty of this is that the office may be quickly revived when next the wind shifts.

The Clinton impeachment has not empowered Congress against the presidency as the Johnson impeachment did for the remainder of the 19th century. Mr. Clinton still routinely bests the Republican Congress. Rather, all tenure and institutions are more fragile. The people more readily distrust whom they elect.

This will haunt and weaken the next president. Thank Nixon.

That successor will be scrutinized for private matters as none before. Thank Mr. Clinton.

Dan Berger is a Sun editorial writer.