With a TV image of Sen. John Cornyn, R-Texas, in the background, Judge Sonia Sotomayor shows the strain of last week's confirmation hearings.

History will show that Sonia Sotomayor would become the first person of Hispanic heritage to serve on the U.S. Supreme Court and only the third woman. But regardless of heritage or gender, what is most important is that Ms. Sotomayor is amply qualified to serve as the court’s 111th justice.

If there had been any doubt, Ms. Sotomayor erased them week in hearings before the Senate Judiciary Committee. As a handful of Republican senators tried to entice her into stepping on oratorical or emotional land mines, she took their toughest shots, showing her legal mettle and judicial temperament.

With poise and deliberation, she endured four days of televised intellectual chess under the hot lights of television crews. She didn’t invent the art form; both Chief Justice John G. Roberts Jr. and Associate Justice Samuel A. Alito were equally imperturbable in their confirmation hearings. Indeed, it’s the only way to survive in today’s sad era of partisan judicial wrangling.

Ms. Sotomayor was flogged with questions focusing on her public comments about what perspective a “wise Latina” would provide from the bench and a painstaking autopsy of the Supreme Court’s recent reversal of her appellate court ruling in Ricci vs. DeStefano, a reverse-discrimation case brought by New Haven, Conn., firefighters.

Ms. Sotomayor has rock-solid credentials: a long career as a prosecutor, trial court judge, civil litigator and 17 years as a federal judge, including the last 11 years on the Second U.S. Court of Appeals in New York. That gives her more judicial experience than any Supreme Court nominee in almost a century. She is a self-avowed workaholic whose driven work habits have meant personal sacrifices.

Her biography alone is compelling: The daughter of Puerto Rican citizens who moved to New York during World War II, she grew up in a public housing project in the South Bronx. She earned merit scholarships to Princeton and Yale Law School. But it is her legal and intellectual experience that makes her fit for the high court.

The usual litmus tests were thoroughly probed: affirmative action, abortion policy, gun rights and gay marriage. As did Mssrs. Roberts and Alito before her, Ms. Sotomayor repeatedly answered that she would “apply the law” rather “make the law” based on court precedents.

Sen. Lindsey Graham, R-S.C., using anonymous comments from lawyers who had argued before her court, raised questions about an intemperate and bullying demeanor. It backfired; Mr. Graham seemed the bully instead. Had she been prone to mean-spirited outbursts, decades of court transcripts would have been trotted out.

Democratic senators were gentle, even fawning, at times, coaxing her into a sort of apology for comments about how a “wise Latina” judge might behave. She called it a “poorly worded” statement that gave some people misperceptions about personal biases.

Few, if any, minds on the committee were changed. A committee vote could come Tuesday, though Republicans may ask for a week’s delay, hoping a skeleton will leap out of the closet at the last minute. Failing that, confirmation is assured. Democrats have the votes, though that should not be the standard.

Regardless of politics, the president has the right to see his appointees confirmed, as long as they are qualified by experience and as long as their views are not out of the mainstream of constitutional thought. We supported Mr. Roberts’ nomination, but had reservations about Mr. Alito’s extreme positions.

Ms. Sotomayor’s record is impeccable and puts her squarely in the mainstream. She deserves prompt confirmation.