Washington ? On the often bumpy road to confirmation to the nation’s highest court, Sonia Sotomayor has a crucial dynamic smoothing her path: ethnic politics.

Republicans, at sea as a party and having lost ground with Hispanic voters, the fastest-growing segment of the population, will have a hard time defeating the woman who would be the first Hispanic justice. And the inevitable partisan fights over Sotomayor’s nomination hold heavy risks for a party striving to draw beyond its mostly white, Southern and conservative base.

Sotomayor will field heavy criticism from right-wing groups and some conservative GOP senators, but strategists in both parties agree that Republicans will have to tread carefully — and won’t likely be able to stop her.

Republicans are “going to have to make a judgment based on what they think her record is, but how they talk about it and how they discuss it is going to be the difference between them alienating Hispanics or sounding reasonable to Hispanics,” said Frank Guerra, a Texas-based GOP strategist who handled outreach for Hispanic voters for former President George W. Bush’s presidential campaigns. “They’re going to have to handle it very deftly.”

Democratic Sen. Chuck Schumer of New York was more blunt in his political assessment for Republicans: “They oppose her at their peril.”

Sotomayor starts out with a powerful numerical advantage. Democrats are on the brink of having 60 votes in the Senate — the number it takes to break a filibuster that could block the nomination.

What’s more, seven Republican senators backed Sotomayor’s 1998 nomination to the appeals court covering New York, Vermont and Connecticut.

Sen. Olympia Snowe, R-Maine, one of those seven, gushed about Sotomayor in a statement Tuesday, saying hers was “an historic selection” and calling her “a well-qualified woman.” She also noted that Rahm Emanuel, the White House chief of staff, had personally called her early in the day to tip her off about the pick — an indication that the push to lock in votes for Sotomayor from Republican senators is already well under way.

Hispanic groups say that Republicans, particularly those from Southern and Western states with large and growing Hispanic populations, will be hard-pressed to oppose Sotomayor given her bipartisan appeal — she was first nominated for a federal court post by President George H.W. Bush — and strong qualifications.

A case in point: Sen. Kay Bailey Hutchison, the Texas Republican who is running to be governor in a heavily Hispanic state. The League of United Latin American Citizens, which honored Hutchison at its February gala, plans to lobby her in person to back Sotomayor and ask their members to urge her to do so, said Lizette Olmos, a spokeswoman.

Hutchison gave no hint Tuesday of her position on Sotomayor’s nomination.

Said Maria Cardona, a Democratic strategist who helped found Hispanics for a Fair Judiciary, a nonpartisan group: “Republicans are going to have to tread very, very carefully on this one. They have already alienated 70 percent of the Hispanic community in this country with the whole issue of immigration.”

Lionel Sosa, another GOP strategist who advised President George W. Bush on Hispanic outreach, said: “Republicans would be idiots for opposing her. … It would be one more nail in the Republican image coffin.”