San Jose U.S. District Judge Lucy Koh, whose rulings in major tech industry legal showdowns have heavily influenced Silicon Valley, was nominated on Thursday to a federal appeals court.

Setting up another possible election-year standoff over a federal judge pick, President Barack Obama nominated Koh to the San Francisco-based 9th U.S. Circuit Court of Appeals. The Republican-controlled Senate would have to confirm Koh, ordinarily a tough sell in a presidential election year and further complicated by the looming prospect of an epic political showdown over the president’s anticipated nomination of a U.S. Supreme Court justice.

Koh’s nomination, along with several other Obama picks for federal appeals courts in recent months, will unfold amid a planned Republican backlash against any nominee the White House forwards for the Supreme Court vacancy created by the death of Justice Antonin Scalia.

But Obama has continued forwarding federal judge nominees to the Senate.

“Judge Lucy Haeran Koh has distinguished herself as a first-rate jurist with unflagging integrity and evenhandedness,” President Obama said in a statement. “I am grateful for her service to the state of California and look forward to adding her considerable wisdom and experience to the Ninth Circuit Court.”

Koh could not immediately be reached for comment.

The 47-year-old Koh, best known for presiding over the Apple v. Samsung patent feud and legal claims against Silicon Valley tech powers over illegal hiring practices, has spent nearly six years on the Bay Area federal bench.

While Koh’s nomination is not considered a surprise in Bay Area legal circles, her confirmation may face long odds. Federal court nominations often get frozen by politics at this stage because of the prospect that another president will have a chance to fill judicial vacancies, although there have been deals cut in the past between Democrats and Republicans to push through some noncontroversial nominees before an election.

Carl Tobias, a University of Richmond law professor, put the odds at about “50-50” that Koh could be confirmed. “The machinations over the Scotus vacancy, generic Republican obstruction of Obama lower court nominees … and the presidential election year make it difficult but not impossible,” he said.

California Sen. Dianne Feinstein, a key Democrat on the judiciary committee, on Thursday pushed the Senate to move “quickly on her nomination.”

Koh may get some bipartisan support. Viet Dinh, a high-ranking Justice Department official during the Bush administration, endorsed her nomination. Former Republican Gov. Arnold Schwarzenegger also backed the nomination. Silicon Valley lawyers voiced their support, as did leaders of national and local Asian bar groups pushing for more representation in the federal courts.

Even if the Senate stalls the nomination, Koh can be renominated if a Democrat takes the White House in the fall. If Koh is confirmed, it will open a spot on the San Jose federal bench.

Koh would fill the only California vacancy on the 9th Circuit, which shapes law for California and eight other Western states and has drawn the ire of conservatives over the years for its liberal leanings.

Obama nominated Koh to the district court in 2010, after she had been recommended by Sen. Barbara Boxer. Koh has political clout in her household — her husband, Mariano-Florentino Cuellar, is a California Supreme Court justice and former Stanford law professor who previously served in the Obama administration.

Koh would become the first Korean-American woman judge on the 9th Circuit. When Koh joined the federal bench, she was the Bay Area’s first Asian-American judge and first female Korean-American federal judge in the nation. Koh was a Santa Clara County judge when she was appointed to the federal judgeship.

As a federal judge, Koh has exerted heavy influence on some of the most significant legal battles involving technology companies in recent years, including presiding over multiple trials in Apple’s patent lawsuit against Samsung over iPhone and iPad technology. That case has reached the U.S. Supreme Court.

Koh also allowed a lawsuit to proceed against Apple, Google, Adobe and other tech firms over illegal hiring practices in a case that ultimately settled. She has not issued any particularly controversial rulings in hot-button issues that can pose problems with Senate Republicans, such as same-sex marriage rights, abortion, affirmative action or the death penalty.

Howard Mintz covers legal affairs. Contact him at 408-286-0236 or follow him at Twitter.com/hmintz.