“The embargo has benefited the Castro regime and hurt the Cuban people,” said Representative Emmer. “We’ve given it plenty of time.”

Despite the executive actions the Obama administration has taken, Cuba continues to face some of the stiffest American sanctions. It is the only country United States citizens are barred from visiting as tourists. The chief executive of Marriott International, Arne Sorenson, who recently visited Cuba for the first time, is among those arguing that the embargo is putting American companies at an unreasonable disadvantage. Foreign businesses are rushing to get a foothold in the Cuban market “to leave as little as possible for American business when the restrictions are lifted altogether,” Mr. Sorenson said in a statement.

Spurred by the same concern, Senator Amy Klobuchar, Democrat of Minnesota, introduced a bill in February that would allow regular commerce with Cuba. “What is going to happen is Americans are going to flock to Cuba, they’re going to be staying in Spanish hotels, eating German food and using Chinese computers,” she said.

For years, Cuban-American lawmakers, who continue to champion the embargo, have dominated policy toward Cuba. Historically, other politicians largely deferred to them because many were less invested in the issue and some feared that taking an anti-embargo position would alienate Cuban-American voters.

Any lawmaker who remains on the fence on the matter should consider the dramatic change in public opinion. A Pew Research Center poll released on July 21 showed that 72 percent of Americans support ending the embargo against Cuba, up from 66 percent in January. While Democrats support President Obama’s effort to normalize relations with Cuba by a wider margin than Republicans, support among the latter is rising. The survey found that 55 percent of conservative Republicans favor ending the embargo, up from 40 percent in January.