Senate Republicans who are asked to respond to President  Trump’s increasingly incendiary pronouncements and actions appear torn or paralyzed. Condemn him, and risk the fate of Sen. Kelly Ayotte, R-N.H., who broke with him and lost a close election in 2016. Remain mute, and alienate moderates who are likely to be crucial to victory in states like Maine and Colorado.

This isn’t the first time that Republican senators have wavered over how to handle a demagogue. In the 1950s, most of his Republican colleagues recognized early that the communist-baiting Sen. Joe McCarthy, R-Wis., was an irresponsible bomb slinger, but they were heartened that he was aiming mainly at Democrats and was arming Republicans with a potent electoral issue. Most also had been chasing communists long before McCarthy stumbled onto the cause, although more politely and productively. So they held their noses and publicly encouraged him to keep hurling, the way nearly all their descendants now remain steadfastly with Trump.

Nobody embodied the push-pull better than Sen. Robert Taft, R-Ohio, the unchallenged leader of his party’s conservative wing. Taft resented McCarthy for having backed the moderate Minnesota Gov. Harold Stassen instead of him in the 1948 presidential primaries, and for his boorish defiance of every norm and protocol sacred to this scion of the Senate and son of a former president and Supreme Court justice. Caught off guard by McCarthy’s reckless charges of communist subversion everywhere, from the State Department to the White House, Taft confided to one friend that Joe “doesn’t check his statements very carefully and is not disposed to take any advice, so that it makes him a hard man for anybody to work with, or restrain.” To others, he prophetically pronounced that the senator from Wisconsin had “made allegations which are impossible to prove which may be embarrassing before we get through.”

But there was a reason Taft – like today’s Senate Majority Leader Mitch McConnell, R-Ky. – was called “Mr. Republican.” Donning his partisan persona, the civil libertarian from Ohio found a stream of rationalizations for continuing to support his colleague or sidestep the issue. Although McCarthy hadn’t unmasked any communists yet, Taft said in early 1950, he ought to “keep talking, and if one case doesn’t work out, he should proceed with another one.” When President Harry S. Truman vilified McCarthy, who had served in the South Pacific during World War II, Taft accused the president of “libeling … a fighting Marine.”

Taft’s prevaricating was perhaps best explained by a Washington acquaintance: “McCarthyism is a kind of liquor for Taft. He knows it’s bad stuff, and he keeps taking the pledge. But every so often he falls off the wagon. Don’t ask me why. I only know that he doesn’t like it and can’t stay away from it.”

Beyond any addiction, there was a simple partisan calculation: After 14 years of feeling like doormats under the Democrats, Taft and other Senate Republican bosses would do nearly anything to hold the majority they reclaimed briefly in 1947 and again in 1953, when Taft briefly became majority leader before passing away that July. Even President Dwight D. Eisenhower was so eager to maintain his congressional majority that he held his tongue publicly – even as he was privately telling his brother and his aides how much he despised the Badger State bully.

The only Republican to take a firm stand against McCarthy was the Senate’s only woman, Margaret Chase Smith of Maine. It would be her proudest moment in the chamber and one for which she would pay dearly. Smith had met McCarthy years before at a dinner party and had not been charmed. The two shared a skepticism about communism, and McCarthy not only named her to the investigations subcommittee, where he was ranking Republican, but also touted her as a future vice-presidential nominee.

Yet “the more I listened to Joe … the less I could understand what he was up to,” Smith said, looking back.

“One day, Joe said, ‘Margaret, you seem to be worried about what I am doing.’ I said, ‘Yes, Joe. I want to see the proof.’ ”

McCarthy: “But I have shown you the photostatic copies.”

Smith: “Perhaps I’m stupid, Joe. But they don’t prove a thing to me that backs up your charges.”

On June 1, 1950, mimeographed remarks in hand, Smith was heading for the members-only train that would take her from her office to the Capitol when she ran into McCarthy.

“Margaret,” he said jauntily, “you look very serious. Are you going to make a speech?”

“Yes, and you will not like it,” she said.

McCarthy, smiling: “Is it about me?”

Smith: “Yes, but I’m not going to mention your name.”

McCarthy, frowning: “Remember, Margaret, I control Wisconsin’s 27 convention votes!”

On the Senate floor, Smith said she wanted to discuss with her colleagues “a serious national condition” that made it “high time for the United States Senate and its members to do some soul-searching – for us to weigh our consciences – on the manner in which we are performing our duty to the people of America. … Those of us who shout the loudest about Americanism in making character assassinations are all too frequently those who, by our own words and acts, ignore some of the basic principles of Americanism: the right to criticize; the right to hold unpopular beliefs; the right to protest; the right of independent thought.”

While saying that “the nation sorely needs a Republican victory” in the 1950 elections, she added, “I don’t want to see the Republican Party ride to political victory on the Four Horsemen of Calumny – Fear, Ignorance, Bigotry and Smear.” Finishing her opening remarks and trying to settle what she later conceded was a fluttering stomach, the ordinarily cautious Smith read a “Declaration of Conscience” that called for civility and bipartisanship and was co-signed by six moderate Republicans.

It was a 15-minute act of gallantry and grit, one that made Smith a model that today’s senator from Maine, Susan Collins, seeks to emulate, and that McCarthy listened to silently from his desk two rows behind Smith’s. But the recriminations were quick and stinging. Columnist and McCarthy friend Westbrook Pegler called her “a Moses in nylons” who “took advantage … of her sex.”

Others suggested that the two had been romantically involved, or she’d wanted to be, and that the speech was personal revenge. McCarthy called Smith and her co-signatories “Snow White and the Six Dwarfs.” His words were reinforced by splenetic action. Using his authority as ranking Republican, in 1951 he dumped Smith from the subcommittee he had named her to, and three years later he helped recruit, finance and promote the candidate who unsuccessfully challenged her in the Republican primary in Maine.

Smith did have defenders. Truman told her that her Declaration of Conscience was “one of the finest things that has happened here in Washington in all my years in the Senate and the White House.” Even more satisfying in that era of glass ceilings, statesman and financier Bernard Baruch said that if a man had delivered the same rebuke Smith had, he’d be the next president of the United States.

In the end, it took McCarthy’s bullying performance during the 1954 Army-McCarthy hearings – and the free-fall it provoked in his polling numbers – for a majority of the Senate to finally stand up to its flame-throwing colleague. Even then, only 22 of the 44 Republicans who had long been his enablers voted to censure McCarthy. Some who didn’t were driven by friendship, others by do-or-die party loyalty, although few by then still worried about the Wisconsinite’s vaunted capacity to exact revenge.

Columnist Murray Kempton sounded a verdict that history has echoed and that McConnell, Collins and their party brethren might weigh. “Men who had feared for years to call against him the verdict of principle called against him now the verdict of expediency,” Kempton wrote. “Even the friends of Joe McCarthy conceded that he was a dirty fellow and a bit of a fraud.”