Between the dramatic raid that killed Osama bin Laden and pro-democracy uprisings from North Africa to the Persian Gulf, the world this spring has been a rapidly changing place.

But change still proceeds with glacial slowness in one of the last vestiges of the Cold War, the half-century standoff between the United States and Cuba.

Indeed, as Cubans here and there mark Friday’s 109th anniversary of winning independence from Spain, hard-liners in both countries still forestall the changes that could enable Cuba to join the global democratic revolution.

In Havana, despite modest changes, President Raul Castro remains firmly in control.

And in Washington, the Republican takeover of Congress and the Obama White House’s increasing focus on the 2012 election have diminished prospects for changing U.S. policy after last year’s abortive congressional effort to relax the 50-year-old American trade embargo.

By moving so slowly, Obama has disappointed many advocates of normalized relations. Like predecessor George W. Bush, Obama seems concerned with alienating the one place where hard-line policies toward Cuba still count: Florida.

This remains true, though national polls in recent years show a majority of Americans favoring normalized relations and ending the embargo and travel restrictions. Even among Cuban-Americans, opinion is split, with younger ones sharing the national consensus.

“The White House has allowed itself to get locked into a bad reading of opinion in Florida and a total disregard of national opinion,” said John McAuliff, executive director of the pro-liberalization Fund for Reconciliation and Development.

Yet this year has seen positive developments in both countries.

In January, Obama made it easier for educational and religious groups to visit Cuba. And Cuba may soon permit its citizens to travel overseas for the first time in 50 years and ease restrictions on selling real estate and automobiles.

In addition, Castro reportedly has agreed to devote a special Communist Party congress next January to considering political reforms, as yet undefined.

Just as closer relations with the West helped end Soviet control of Eastern Europe, increasing personal and economic exchanges between Cuba and the U.S. can’t help but produce positive results.

But the GOP takeover of the House ended any prospect of legislation to end the embargo. A measure expanding agricultural trade and easing travel restrictions seemed close to passing the House last year but never came to a vote and faced strong Senate barriers.

Advocates of closer ties hailed the administration’s January decision to ease travel restrictions. But McAuliff noted that “the many more pages devoted to specific licenses reflect a control rather than a facilitation attitude inconsistent with the goal of purposeful travel.”

Last week, Obama seemed to harden his administration’s line, telling Univision, “For us to have the kind of normal relations we have with other countries, we’ve got to see significant changes from the Cuban government, and we just have not seen that yet.”

One ongoing problem is Cuba’s arrest of Alan Gross, an American subcontractor for the Agency for International Development convicted and sentenced to 15 years for illegally importing computer gear.

That has complicated relations like the 1996 incident in which Cuba shot down two planes from a U.S.-based, anti-Castro volunteer group, killing four at a time many speculated President Bill Clinton, if re-elected, would ease the embargo. It never happened.

Bush, whose strong support from Florida’s Cuban-Americans helped him win the 2000 election, maintained a hard-line stance, but Obama pledged “a new beginning” in 2009.

Subsequent change has been modest. Florida again looms as a vital battleground state in 2012, and influential Florida Democrats share the GOP’s hard-line stance, notably Rep. Debbie Wasserman Schultz, the new Democratic national chair and a critic of Obama’s decision to ease travel restrictions.

So, again, it appears that when it comes to U.S. relations with Cuba, local political considerations trump the national interest.

Carl P. Leubsdorf is the former Washington bureau chief of the Dallas Morning News. Readers may write to him via email at: carl.p.leubsdorfgmail.com.