WASHINGTON — President Obama is set to end his term with dozens fewer lower-court appointments than both Presidents Bill Clinton and George W. Bush achieved in their first four years, and probably with less of a lasting ideological imprint on the judiciary than many liberals had hoped for and conservatives had feared.

Mr. Obama’s record stems in part from a decision at the start of his presidency to make judicial nominations a lower political priority, according to documents and interviews with more than a dozen current and former administration officials and with court watchers from across the political spectrum. Senate Republicans also played a role, ratcheting up partisan warfare over judges that has been escalating for the past generation by delaying even uncontroversial picks who would have been quickly approved in the past.

But a good portion of Mr. Obama’s judicial record stems from a deliberate strategy. While Mr. Bush quickly nominated a slate of appeals court judges early in his first year — including several outspoken conservatives — Mr. Obama moved more slowly and sought relatively moderate jurists who he hoped would not provoke culture wars that distracted attention from his ambitious legislative agenda.

“The White House in that first year did not want to nominate candidates who would generate rancorous disputes over social issues that would further polarize the Senate,” said Gregory B. Craig, Mr. Obama’s first White House counsel. “We were looking for mainstream, noncontroversial candidates to nominate.”