Listen carefully to the Republican leaders and presidential hopefuls roaring with outrage over President Obama’s courageous decision to normalize relations with Cuba; listen very carefully, because no matter how long or how closely you listen to them, there is one thing you will surely never hear.

You will never hear a new idea – or any plausible idea – about bringing liberty, democracy, and prosperity to the suffering Cuban people.

Instead, the furious denunciations of the president’s initiative from his adversaries reveal only an intellectual void on Capitol Hill, where the imperatives remain partisan and cynical. Everyone paying attention has known for decades that the frozen relationship between the United States and Cuba has accomplished nothing – except possibly the prolongation of the Castro regime, which has long considered the embargo a plausible excuse for its own economic failures – and viewed the United States as a politically convenient enemy.

Anyone who has visited the island knows that the Cubans wish nothing more than to see the embargo lifted, because they know it has done nothing to advance their liberty or prosperity – just the opposite.

As former president Bill Clinton likes to say, the definition of insanity is to keep doing the same thing and expecting a different result. (He wanted to normalize relations as president, but the Cuban government clearly didn’t.) The U.S. government has been doing the same thing in Cuba for 54 years, yet the Republicans still don’t think that was long enough. They haven’t explained how or why – or when – their policy will achieve a different result.

Opponents of change have also failed to justify why treating Cuba so differently from other – and in various respects, worse – authoritarian regimes with which we maintain not only vigorous diplomatic relations but massive trading partnerships and even military cooperation. The conduct of those governments is arguably more repressive in important respects; there is, for instance, less religious freedom in China or Saudi Arabia than Pope Francis found in Cuba.

To browse human rights findings from the State Department’s annual reports or the online files maintained by groups like Human Rights Watch and Amnesty International is to find at least a dozen countries with atrocious human rights records, from Chad to Turkmenistan. But the United States maintains diplomatic and trade relations with all of them.

Indeed, Republican leaders and businessmen – notably including members of the Bush family – have profited handsomely from investment in countries like China and Saudi Arabia for many years, with scarcely a peep about human rights violations in those places. It is impossible to forget how the first President Bush toasted the Chinese regime, immediately following the massacre in Tiananmen Square – and how his opportunistic family members showed up in Beijing and Shanghai, looking for a deal.

With the liberation of more than 50 political prisoners – along with USAID worker Allen Gross and an unnamed American spy – the Cubans have suddenly improved their human rights performance, while the Chinese continue to inflict horrendous repression and even torture on Tibetans, Uighurs, and Han Chinese who dare to dissent. (Many of our leading Republicans don’t object to torture, of course, unless it is perpetrated in foreign countries. Sometimes.)

House Speaker John Boehner accused the president of making “another mindless concession to a dictatorship.” What seems entirely mindless, however, is his insistence that we dare not abandon an unworkable and destructive strategy. No boycott observed and enforced by one country alone – even a powerful country like the United States – is ever going to prevail.

That is among the reasons why international human rights organizations, always the most consistent and implacable critics of Castro’s abuses, have long advocated engagement rather than embargo. As Human Rights Watch notes on web pages devoted to detailing those abuses, U.S. policy has imposed “indiscriminate hardship on the Cuban people” since 1961, “and has done nothing to improve the country’s human rights.”

Not long after the president concluded his historic speech – among the most lucid, logical, and inspiring he has delivered in his second term – a spokeswoman for Amnesty International called his new approach “the best opportunity in half [a] century for human rights change in Cuba.”

Designed to quarantine the Cuban government, the policy that failed for five decades has only succeeded in isolating the United States from the rest of the world. Its end is long overdue.