WASHINGTON – When President Bush’s nominee for chief justice of the United States, Judge John Roberts Jr., takes his seat before the Senate Judiciary Committee Monday, Republican supporters of Judge Roberts will be happy if either one of two apparently contradictory scenarios unfold.

On the one hand, some Republican officials said, the hearing will be an opportunity for senators to bring civility back to the process of confirming federal judges: A dignified hearing could alleviate the acrimony that has characterized hearings over the last two decades.

“We want an end to that partisan politicization of the judicial process in the Senate because of the fact that the president, the nominees, and the institution of the Senate all deserve respect,” a senior Republican official in the Senate said. “This is not a political campaign, and a judicial nominee is not a politician.”

Other Republican activists say that few issues play better among swing voters than the perception that activist judges have assumed too much power in recent years. This concern gave Republicans the majority in the Senate three years ago, they say, and voters are now poised to turn on as many as 10 more Senate Democrats next year based on their treatment of Judge Roberts.

“If you’re Senator Nelson in Nebraska, I think you’re sweating bullets over a huge food fight orchestrated by Senator Schumer or Senator Kennedy attacking John Roberts for his views,” the executive director of the Committee for Justice, Sean Rushton, said. “It’s not enough for these guys to quietly vote with the president. At some point, voters are going to say ‘We need someone to stand up to Ted Kennedy.'”

Barring a surprise revelation about Judge Roberts, both groups – those who say they want civility and those who think Democratic partisanship will help Republicans politically – say the hearing on Judge Roberts has the potential of solidifying recent Republican gains in the Senate and of clearing the way for easier confirmation hearings for conservative judges in the future.

“It is a win-win situation,” the director of the Judicial Confirmation Network, Gary Marx, said. “We’re going to win either way on this because if the other team acts really crazy at the hearing we’ll still win at the end of the day politically. If some of these Democratic senators vote with us, that’s great. But if they don’t, that vote can be used against them in 2006, just as it was in 2004 and 2002.”

Democratic leaders in the Senate have pointed to the fact that none among their ranks have said they will vote on Judge Roberts as a sign of restraint ahead of the hearing. Republican activists say it is more likely that many Democrats are still calculating the potential political risk of voting against the nominee.

“There are about 10 senators that we think are really swing votes on this issue,” Mr. Marx said. “I think we’ll end up getting about half of them.”

Mr. Marx listed several Democratic senators that Republican activists are focused on ahead of the hearing on Judge Roberts, including, Senator Nelson of Florida; Senator Byrd from West Virginia, Senator Pryor of Arkansas; Senator Nelson of Nebraska; Senator Salazar of Colorado; Senator Baucus in Montana, and Senator Conrad of North Dakota.

Democrats are not willing to concede that next year’s elections have figured into their calculation. “Senator Pryor believes he has a duty to uphold as it pertains to advise and consent,” a spokesman for Mr. Pryor, Rodelle Mollineau, said. “He’s going to look at John Roberts’s nomination as he’s looked at countless others before and make a determination based on qualifications, judicial temperament, and the ability to be fair and impartial. Political pressure will have nothing to do with it.”

Some political observers have speculated that the political hit the Bush administration has taken over the federal response to Hurricane Katrina could prompt the president to choose a nominee for the second open seat on the Supreme Court with someone who is perceived as a moderate.

Seeing a similar opening, leading Senate Democrats yesterday issued an open letter to Mr. Bush urging him to choose a “consensus” nominee to replace Justice O’Connor.

Republican activists said they do not expect the president to yield to the requests of Democrats. At the same time, they said they fear Mr. Bush might also look to tweak conservative activists who bristle at the suggestion of nominating the U.S. attorney general, Alberto Gonzales, to fill Justice O’Connor’s seat.

Manuel Miranda, a former counsel to the Senate’s majority leader, Senator Frist, said that if the president chose Mr. Gonzales, he would “divide in a long-lasting manner the conservative movement.” Mr. Miranda went on to say that any conservative group that says otherwise is not telling the truth.

At least one pro-Roberts group said for the first time yesterday that it would support Mr. Gonzales as a nominee. Speaking in a panel discussion on the judicial nominations at the National Press Club yesterday, Mr. Rushton, said his group “will support Attorney General Gonzales if he’s the White House’s nominee.” Smiling, Mr. Rushton added, “Let’s leave it at that.”