Judge Sonia Sotomayor was expected to win Senate confirmation as early as Thursday as the first Hispanic US Supreme Court justice, in a major victory for President Barack Obama.

The 55-year-old appeals court judge was to become the third woman to sit on the bench that serves as the final arbiter of the US Constitution and is called upon to decide bitter feuds on volatile issues like gun rights and abortion.

Support from all of Obama’s Democratic allies and a handful of Republicans meant the outcome was never seriously in doubt — though the final days brought increasingly harsh debate over the place of race in the nomination.

Republican Senator James Inhofe took aim at Sotomayor’s much-quoted comment that she hoped a "wise Latina" judge could be a better judge than a white male, and bluntly declared: "I consider that racist."

The only Hispanic Democratic senator, Robert Menendez, joined leaders of major Latino groups to warn Republicans that they will "pay a price" in coming elections for voting against the groundbreaking nomination.

"I believe the Republicans will pay a price for saying ‘no’ to this judge," and to Obama’s policies in general, Menendez said in Spanish at a press conference in the US Capitol.

The Cuban-American New Jersey lawmaker said "maybe less than 10" of the chamber’s 40 Republicans will vote to confirm Sotomayor, who is the daughter of migrants from Puerto Rico.

Some Republicans have worried that opposition to Sotomayor may hurt the party with Hispanic voters, who could play a decisive role in the 2010 mid-term elections and the 2012 presidential vote.

"In last year’s elections, the road to the White House in large part came through the Latino community," said Menendez. "We need to know who is with us, and who is not."

Hispanic Americans, who voted about 2-to-1 for Obama over Republican Senator John McCain in the 2008 White House race, do not vote as a bloc. And most — more than 60 percent — are Mexican-American.

But because the Hispanic sociological group is the fastest-growing US minority, lawmakers are keen to try to line up support.

Janet Murguia, head of the top US Hispanic rights group National Council of La Raza, said Sotomayor’s nomination had galvanized and united the diverse Latino population and cautioned Republicans about the coming vote.

"I think the Republican Party is at a crossroads with our Latino community," she said. "This vote will matter and it will be long remembered."

Republican Senator Kit Bond of Missouri announced he would vote for confirmation even though he disagreed with her views, bringing to seven the number of Republicans backing Sotomayor.

"I will support her, I’ll be proud for her, the community she represents, and the American Dream she shows is possible," he said. "I urge my colleagues to do the same."

Republican Senator Jon Kyl, his party’s number two in the Senate, said that while "every American should be proud that a Hispanic woman has been nominated," lawmakers "must evaluate Judge Sotomayor on her merits, not on the basis of her ethnicity."

Republicans also underlined that Democrats blocked a vote to confirm a Hispanic nominee, Miguel Estrada, to be an appeals court judge.

"Because he had been nominated by a Republican, Estrada got no points for his compelling personal story," said Senate Minority Leader Mitch McConnell.

Democratic Senators Ted Kennedy and Robert Byrd could be no-shows at the vote because of health reasons.

Meanwhile, a CNN poll released Wednesday found that 51 percent of US respondents favored Sotomayor being approved. Thirty-six percent opposed her appointment and 14 percent had no opinion.