The other day, Senate Majority Leader Robert J. Dole (R-Kan.) wrote a letter to the secretary of state, sounding the call to arms on Angola.

Bob Dole? This is the realist who talks about raising taxes and who knows better than most what Gramm-Rudman- Hollings does to $10 million to $15 million for a tribal war in Africa? This is the man who defied the administration so successfully on renewal of the Voting Rights Act that super-liberal Joe Rauh said he would be tempted to vote for him for president?

And that, of course, is the key. The manager of the Senate would be president, and like every member of his party, he knows that the nomination comes from the right. Said a bemused colleague, "That letter was written as an enclosure in a right-wing mailing."

The right froths at the mouth over Jonas Savimbi, leader of the UNITA rebels who want to oust Angola's Marxist government. Deprived of victories against abortion, school prayer and creeping wimpiness, they demand action in the bush. Former U.N. ambassador Jeane J. Kirkpatrick, their Thomas Paine, sent the recent Conservative Political Action Conference into a frenzy when she said, "Real assistance means real weapons . . . real helicopters . . . real ground-to air missiles."

But that's Jeane Kirkpatrick. And here's Dole in his letter to George P. Shultz: "With the imminence of a new communist offensive in Angola, it is imperative that the United States begin immediately to provide concrete assistance to the Angolan democratic resistance forces . . . . "

Dole is too sensible to think that assistance, overt or covert, would change the equation or counter the scandal of a U.S. alliance with South Africa.

But common sense is often the first casualty in the war for higher office, and Dole's rivals for the 1988 nomination have established strong beachheads on Angola. Vice President Bush, of course, is marching in lockstep with President Reagan, Savimbi's No. 1 fan, who talks openly of covert aid.

Rep. Jack Kemp (R-N.Y.), who seemed to be the idol of the conservatives at the Dallas convention but has fallen back in the face of Bush's ferociously obsequious courtship, is coauthor of a bill that would give Savimbi $27 million in overt aid.

The rational position comes from Sen. Patrick J. Leahy (D-Vt.): "We must avoid embracing every person who arrives in Washington in fatigues, denouncing communism and quoting Thomas Jefferson."

Savimbi is paying a Washington public relations firm $600,000 to counter his past anti-American rhetoric and blur his record as a Maoist. He has also learned to speak disapprovingly of apartheid while taking arms from South Africa. The imperatives of running for the presidency have brought Dole around to the view that helping a comic-opera jungle lord is "imperative."

On the Democratic side, hopefuls are saying startling and image-adjusting, if more constructive, things. An example is the sudden emergence of Sen. Sam Nunn (D-Ga.) as a champion of Corazon Aquino in the Philippines. While Reagan was trying to decide who committed the fraud, Nunn wrote him a blazing letter, accusing Philippine President Ferdinand Marcos of "making an all-out effort to steal the election."

Those are plain facts to everyone save Reagan, but Nunn, a defense Democrat, doesn't usually defy the president. If there were a Caution Party, he would be its leader. And here he is pulling for someone who isn't sure about U.S. bases and is calling people into the streets. Nunn is much mentioned as a 1988 prospect. The nomination of his party frequently comes from the left, which has thought of him as the voice of the Pentagon.

Similar considerations may have formed the recent statement by Arizona Gov. Bruce Babbitt, who is looking ahead and has a reputation as a "centrist." But there was nothing "centrist" about his recent blast on Nicaragua. The administration's public-relations geniuses dreamed up sending National Guardsmen on annual maneuvers to Honduras, near the Nicaraguan border. It seems a way of involving ordinary people in an unpopular Central American policy. Babbitt, who has allowed Arizona guardsmen on the outing but not near the border, says that "those behind it hope the soldiers would be . . . killed and that their deaths could provide the pretext for a war."

No liberals have said anything as strong, although they may now. Governors don't like their citizens coming home in boxes.

Elections are better than anything, except hangings, for concentrating the minds of politicians.