Obama is facing crucial constitutional tests on key parts of his agenda. Lawsuits over the president’s domestic policy centerpiece, a new national health program, and his policy for handling terrorism suspects are expected to land at the court soon. Legal defeat on either would be a serious setback to the president’s agenda.

Kagan’s mentor and former boss, the late Justice Thurgood Marshall, also served as solicitor general before ascending to the high court, and recused himself in 57 percent of cases in his first year, according to a Newsweek analysis.

White House press secretary Robert Gibbs said Obama took the issue into consideration when he looked at Kagan for the nomination.

“The president had to make a decision similar to past presidents that have tapped solicitor generals to serve on the high court,” Gibbs said. “Next year, I think we anticipate recusals in about a dozen cases, and then maybe less than half of that in the year after that.”