Just a year ago, at a memorial service for Nelson Mandela in South Africa, President Barack Obama set tongues wagging by greeting Cuba’s President Raul Castro with a handshake. That small gesture caused some to wonder if a little thaw might be possible in the ice-cold war that has defined U.S. relations with its island neighbor for more than a half century.

Declaring that the policies of the past — a trade embargo, thorough isolation — have not worked in those 53 years, Obama on Wednesday announced a momentous shift in attitude toward the Communist-led nation.

He intends to set in motion policies that would begin to normalize relations, establish embassies and recognize that the U.S. and Cuba have joint interests in the hemisphere and the world that would benefit both countries if allowed to speak and work together.

Coinciding with prisoner swaps, and reportedly inspired in part by whispers from Pope Francis, Obama’s action is sure to face stiff opposition in Congress. But it’s long overdue and will help make at least our part of the world better.

Obama, at times speaking directly to the Cuban audience as well as those in this country, called “on Cuba to unleash the potential of 11 million Cubans.”

Most Cubans on the island have known little more than oppression and relative poverty under the dictatorship begun by the elder Castro brother, Fidel, after the revolution of the late 1950s.

In reacting to the news, the gnarliest of Republican opponents seem exceedingly out of touch with a majority of Americans and with reality. Despite his Cuban-American heritage, Florida’s Sen. Marco Rubio could do little more than grandstand on Wednesday. He belittled the president, saying Obama was “willfully ignorant of the way the world works.” To hand normalized relations to the Cubans, Rubio said, would preserve that government’s iron-fisted rule for decades to come. How can Rubio’s political naivete be taken seriously?

Sen. Pat Roberts of Kansas has yet to be heard from, but he should speak up and break ranks with the most vocal of his GOP brethren. In the past, Roberts has recognized the business potential for Kansas farmers in a future under which the U.S. and Cuba can get along. Kansas farmers and ranchers — and those in Missouri, as well — have a lot to teach the Cubans, whose agricultural infrastructure is woefully underdeveloped.

Obama’s speech was one of his strongest of recent months, another important display in his new period of lame-duck boldness.