The caning of self-righteous Massachusetts abolitionist Charles Sumner by hot-tempered Carolinian Preston Brooks signaled that civil war was inevitable in America. Brooks, if you remember your history, rained blow after blow upon the seated Sumner until his cane shattered and the northern senator lay bloody and senseless in the aisle of a nearly deserted Senate chamber one afternoon in 1856.

Even more telling as augury of the future was the aftermath of that violent attack: Brooks' southern constituents hailed him as hero, gave him gifts of more canes, reelected him to Congress. Sumner, confined for years to a wheelchair, his spine nearly mutilated, his brain area damaged, recovered to become hero and Senate firebrand of the North.

I concede it to be stretching the allusion, but that historical picture came disturbingly to mind last week at the opening of the second and final session of the 99th Congress. There, paradoxically, given the seeming tranquility of that opening day, was evidence of the underlying tensions and frustrations that permeate Congress and all of official Washington these days.

Shortly after 2 p.m., when the Senate was nearly deserted and the galleries almost empty, Pat Moynihan of New York rose behind his small desk at the rear of the chamber, beneath the clock. Gripping his chair, he delivered a point of personal privilege. He was defending his honor, his record of patriotism, his military service dating from his 17th birthday, his votes over many years in the Senate for a strong American defense. Passion and anguish marked his words.

The idea that Moynihan -- a great scholar of government who has served Republican and Democratic presidents inside the White House, as ambassador to India, as U.S. emissary to the United Nations and as a senator, always with highest distinction -- felt impelled even to recall some of that record underscores the charged emotions in Washington today.

The raw nerves among lawmakers and policy-makers are simply explained: the specter of Gramm-Rudman-Hollings and the excruciating dilemmas it poses. Reduce budget deficits by cuts alone, the president still insists . . . and let there be no tax increases . . . and let defense spending be maintained or increased . . . and let Social Security benefits be preserved. And all this miracle takes place in a crucial election year where courage and independence are diminishing political commodities and everyone knows that, on this issue, there are no easy winners on any votes.

Moynihan's act of self-defense grew out of Gramm-Rudman-Hollings, too. He was responding to an exchange the previous Sunday on NBC's "Meet the Press" with Texas' Democrat-turned-Republican, Phil Gramm. In defending the bill that bears his name, Gramm made support of the legislation a matter of patriotism. He described himself as one of the country's strongest supporters of national defense; then, looking at Moynihan, who voted against the bill, labeled him "one of the weakest."

In the opening-day Senate scene two days later, a handful of Democratic senators arose to defend Moynihan and to make a common and broader political point. They all warned, as did Moynihan, of the dangers of bitter division arising in this session of Congress.

"Let us not take this most difficult and trying and testing of sessions and turn it into name-calling, accusation, and innuendo," Moynihan said. "We lived through that in the period of Joe McCarthy. We have had enough of it around here already."

Robert C. Byrd of West Virginia, the only senator in this session to have served as majority and minority leader, delivered a lecture about why Senate rules require its members to speak in the third person when addressing or referring to each other and thus avoid acrid, embittered, destructive debate. Then he said:

"I am concerned about this session if it is going to be one in which senators cast aspersions upon each other. It could become very personal about such matters, and it should not. I do not question the patriotism of Democrats or Republicans who voted for Gramm- Rudman or against Gramm-Rudman or for appropriation bills . . . . If there is one thing we want to avoid doing in this body, it is just that.

"This is a body which depends greatly, and has over the decades, on the camaraderie -- perhaps not that so much as on patience, courtesy and comity toward each other. That is the only way this body can operate. If it becomes a body in which personalities are attacked and things are said that impugn another senator's good faith or patriotism, Mr. President, this Senate is going to continue going downhill if that is what is going to happen here."

J. James Exon of Nebraska, saying he had just listened to a radio report quoting President Reagan as warning Republican leaders that "if they didn't follow his mark on defense, they would not be good Americans" and also that the Soviets will be watching their votes, added:

"I am very fearful, Mr. President, that we are going to have, as the minority leader has indicated, a tremendously stressful session."

We're not about to replay the bombardment of Fort Sumter, and this isn't the Civil War revisited. But not since the divisive Vietnam period, and maybe since the poisonous era of character assassination that was McCarthyism, do tempers seem to have run so high so early in a political year in Washington. The members are correct in worrying about the dangers of a stressful session. Last year, we witnessed the Congress of failure, of do-nothing. This year, we face the Congress of chaos.

NOTE: Readers who follow these columns will find succeeding installments each Wednesday instead of Sunday.

I also want to note the unusually heavy and almost uniformly unfavorable reader response to my recent column crediting Reagan's leadership qualities with restoring the prestige and power of the presidency after a long period of perceived failure and political impotence. With the single exception of a corporate senior executive based in Connecticut, readers from Hawaii to Florida wrote to express indignation or outrage at such an analysis. One closer to here summed up the collective feelings by calling it "your worst column ever." That includes much territory, considering the many contenders I've supplied.

I cite this because it strikes me as evidence of the other, albeit minority, side of Reagan's high personal popularity. On the basis of this random sampling, a core of articulate citizens opposes policies of his presidency and is frustrated by favorable media comment about him. This opposition appears to have grown as his popularity soars. Virtually all cited budget deficits as a national crisis and expressed anger that Reagan seems to have escaped responsibility for it.