BUFFALO — New York Republicans on Friday nominated Wendy E. Long to challenge Senator Chuck Schumer, a Democrat.

It will be the second Senate bid for Ms. Long, 55, a New York City lawyer who was chosen at the Republican’s nominating convention here. She was beaten decisively by Senator Kirsten E. Gillibrand, a Democrat, in 2012.

Ms. Long, who once clerked for Justice Clarence Thomas at the Supreme Court, was a press secretary to two senators, William L. Armstrong of Colorado and Gordon J. Humphrey of New Hampshire, both Republicans.

On Monday, New York Democrats nominated Mr. Schumer to run for a fourth term. He has $24 million in his campaign account and is heavily favored in a state where Democrats outnumber Republicans two to one.