Senator Tom Cotton of Arkansas has blocked legislation that would have made Daylight Saving Time permanent across the United States, preventing the Senate from advancing the bill by unanimous consent.

The Republican senator objected to a request by Senator Rick Scott of Florida to pass the Sunshine Protection Act, which would eliminate the biannual clock changes and keep Daylight Saving Time in force year-round. Because the vote needed to be unanimous, Mr. Cotton’s move effectively killed the bill’s chances of quick passage in the Senate.

“If permanent Daylight Saving Time becomes the law of the land, it will again make winter a dark and dismal time for millions of Americans,” Mr. Cotton said in his floor speech.

Central to Mr. Cotton’s argument was the nation’s brief experiment with permanent Daylight Saving Time in 1974, which he called an “abject failure.”

“In January of 1974, millions of Americans traveled to work and school in darkness,” the senator said. “Commuter trains were delayed. Schoolchildren carried flashlights. Tragically, some of these kids were struck by cars and killed while walking to school in the dark.”

The experiment, originally intended to last two years, was repealed after less than one year following public backlash. Mr. Cotton said opinion polls showed support for permanent Daylight Saving Time fell by 30 percentage points in just three months.

While Mr. Scott, joined by Senators Sheldon Whitehouse of Rhode Island and Tommy Tuberville of Alabama, attempted to advance the measure, Mr. Cotton argued that permanent Daylight Saving Time would be particularly harmful to residents of his home state and others across the country.

“For many Arkansans, permanent Daylight Savings Time would mean the sun wouldn’t rise until after 8 or even 8:30 a.m. during the dead of winter,” he said. “Three months out of the year, kids in towns like Bentonville, Fayetteville, and Fort Smith would start school ahead of the sun.”

The senator painted an even bleaker picture for northern and western states: “The sun wouldn’t rise until nearly 9 o’clock during winter in Seattle. In Grand Rapids, the sun would rise as late as 9:15 a.m., and in Williston, North Dakota, they would not see the sun until almost 9:45 a.m.”

Mr. Cotton said the darkness would be “especially harmful for schoolchildren and working Americans,” as well as “construction workers, farmers, and others who rise before the sun or need the sun to work.”

A cross-party coalition of lawmakers has been working for years to make Daylight Saving Time permanent, which would provide more evening daylight while reducing morning sunlight and eliminate the twice-yearly clock changes.

The effort gained renewed momentum this spring when President Trump endorsed the concept, calling the changing of the clocks “a big inconvenience and, for our government, A VERY COSTLY EVENT!!!”

Mr. Scott cited states’ rights as a primary reason for supporting the legislation. “It allows the people of each state to choose what best fits their needs and the needs of their families. The American people are sick and tired of changing their clocks twice a year. It’s confusing, unnecessary, and completely outdated.”

While acknowledging that most Americans dislike the biannual clock change, Mr. Cotton argues that permanent Daylight Saving Time is not the solution. “Not every human problem has a legislative solution,” he said. “Sometimes we have to live with an uneasy compromise between competing priorities and interests.”

Mr. Cotton concluded with a story about an 11th-century king who united Britain, Denmark and Norway.

“It brings to mind the story of King Canute, who wanted to teach his sycophants a lesson about the limits of mankind’s power. He famously set his throne on the seashore and forbade the tide from coming in. Of course, the tide nonetheless came in, and, as a historian recounted, “disrespectfully drenched the king’s feet and shins,'” he said on the Senate floor.

“The moral of the story, the king reminded his fawning court, is that ‘the power of kings is empty and worthless, and there is no king worthy of the name save Him by whose will heaven, earth and sea obey eternal laws.’ Good King Canute’s wise words are as true now as they were then. No earthly ruler — not even this Congress — can alter the movements of the heavens — not today, not in 1974, not ever,” Mr. Cotton said.