Increasingly, across this city, the "I" word is being heard.

Impeachment is being brought up by Republicans outraged over Barack Obama's usurpations of power and unilateral rewriting of laws. And Obama is taunting John Boehner and the GOP: "So sue me."

Democrats are talking impeachment to rally a lethargic base to come out and vote this fall to prevent Republicans from taking control of the Senate, and with it the power to convict an impeached president.

Still, Republicans should drop the talk of impeachment.

For the GOP would gain nothing and risk everything if the people began to take seriously their threats to do to Barack Obama what Newt Gingrich's House did to Bill Clinton.

The charges for which a president can be impeached and removed from office, are "Treason, Bribery, or other high Crimes and Misdemeanors."

With Bill Clinton, the impeachers had a solid case of perjury.

With Richard Nixon, they had a preponderance of evidence that, at least for a time, he had sought to obstruct justice in the investigation of the Watergate break-in.

Article II of the impeachment of Richard Nixon was for misuse of the IRS in what turned out to be futile and failed attempts to have the agency harass political enemies by having them audited.

As yet there is no evidence Obama knew of the IRS plot to delay and deny tax exemptions to Tea Party groups, which would be an abuse of power and a trampling upon the constitutional rights of Tea Partiers, who were denied the equal protection of the laws.

The GOP response to the lost emails of Lois Lerner and crashed computers that went missing should be a drumbeat of demands for the appointment of an independent counsel, not an impeachment committee in the House.

Obama claims he did not learn of the IRS abuse until years after it began, and weeks after his White House staff learned of it.

In the absence of those emails, the claim cannot be refuted.

In the Benghazi scandal, the president's defense is the same.

He had no idea what was going on. And cluelessness appears here to be a credible defense. Two weeks after the Benghazi atrocity, Obama was at the U.N. still parroting the Susan Rice line about an anti-Muslim video having been the cause of it all.

Has the president unilaterally rewritten the Obamacare law, while ignoring the Congress that wrote it? Indeed, he has.

But would a Republican Party that failed and folded when it tried to use its legitimate power of the purse to defund Obamacare really stand firm in an Antietam battle to impeach a president of the United States?

Or is this just "beer talk"?

Impeachment is in the last analysis a political act.

The impeachment of Nixon was a coup d'etat by liberal enemies who, though repudiated and routed by the electorate in 1972, still retained the institutional power to break him and destroy his presidency.

And, undeniably, he gave them the tools.

In the case of Nixon, political enemies controlled both houses of the Congress. Washington was a hostile city. Though he had swept 49 states, Nixon lost D.C. 3-to-1. The bureaucracy built up in the New Deal and Great Society was deep-dyed Democratic.

Most crucially, the Big Media whose liberal bias had been exposed by Nixon and Vice President Spiro Agnew were hell-bent on revenge.

All three power centers—the bureaucracy, Congress, the Big Media—worked in harness to bring Nixon down.

No such powerful and hostile coalition exists today with Obama.

In 2008, Obama carried D.C. 24-to-1 over John McCain. The While House Correspondents Association has at times behaved like an Obama super PAC. Liberal Democrats dominate the bureaucracy and control the Senate.

Any Republican attempt at impeachment would go up against a stacked deck. And the GOP would be throwing away a winning hand for a losing one.

For while the American people have shown no interest in impeaching Obama, they are coming to believe they elected an incompetent executive and compulsive speechmaker who does not know what the presidency requires and who equates talk with action.

With the economy shrinking 3 percent in the first quarter, with Obama sinking in public approval, and with the IRS, NSA and VA scandals bubbling, why would Republicans change the subject to impeachment?

The effect would be to enrage and energize the Democratic base, bring out the African-American vote in force and cause the major media to charge the GOP with a racist scheme to discredit and destroy our first black president.

Does the GOP really want a fight on that turf, when they currently hold the high ground? If you are winning an argument, why change the subject?

If the nation is led to believe Republicans seek to gain the Senate so they can remove Barack Obama from office after a GOP-led impeachment, then Republicans are not likely to win the Senate.

Maybe that is why the Democrats are wailing about impeachment.

Republicans should take away the football.

Patrick J. Buchanan is the author of the new book "The Greatest Comeback: How Richard Nixon Rose From Defeat to Create the New Majority," to be released tomorrow.