CINCINNATI — Three federal judges weighing arguments in a landmark gay marriage hearing Wednesday peppered attorneys on both sides with tough questions, with one judge expressing deep skepticism about whether courts are the ideal setting for major social change and another saying the democratic process can be too slow.

The judges in the 6th U.S. Circuit Court of Appeals considered arguments in six cases from Michigan, Ohio, Kentucky and Tennessee, setting the stage for historic rulings in each state that would put more pressure on the U.S. Supreme Court to decide the issue once and for all. Wednesday’s hearing was the biggest so far on the issue.

The cases pit states’ rights and traditional conservative values against what plaintiffs’ attorneys say is a fundamental right to marry under the U.S. Constitution.

While questions and comments from two of the judges all but gave away how they’ll rule, one in favor of gay marriage and one opposed, Judge Jeffrey S. Sutton vigorously challenged some of each side’s assertions.

Sutton repeatedly questioned attorneys for the same-sex couples whether the courts are the best place to legalize gay marriage, saying that the way to win Americans’ hearts and minds is to wait until they’re ready to vote for it.

“I would have thought the best way to get respect and dignity is through the democratic process,” said Sutton, a George W. Bush nominee. “Nothing happens as quickly as we’d like it.”

Judge Martha Craig Daughtrey, a Bill Clinton nominee, said that historically, courts have had to intervene when individual constitutional rights are being violated, such as overturning state laws against interracial marriage and giving women the right to vote, pointing out that the latter took decades.

“Do you have any knowledge of how many years I’m talking about, going into every state, every city, every state board of elections, for 70 years?” she said. “It didn’t work. It took an amendment to the Constitution.”

Besides, gay marriage already is legal in more than a quarter of the states, and “it doesn’t look like the sky has fallen in,” Daughtrey said.

Constitutional law professors and court observers say that the 6th Circuit could be the first to uphold statewide bans on gay marriage following an unbroken string of more than 20 rulings in the past eight months that have gone the other way.

They point to Sutton, the least predictable judge on the panel. In 2011, he shocked Republicans and may have derailed his own chances to advance to the U.S. Supreme Court when he became the deciding vote in a ruling that upheld President Barack Obama’s health care law.

If the 6th Circuit decides against gay marriage, it would create a divide among federal appellate courts and put pressure on the U.S. Supreme Court to settle the issue in 2015.