Washington ? President Barack Obama has begun conversations with potential Supreme Court nominees, a senior administration official said Tuesday, signaling an upswing in the president’s consideration of an already coalescing list of candidates.

Obama’s review will throttle ahead this morning when he meets privately with the top Democrat and Republican in the Senate along with the chairman and ranking member of the Senate Judiciary Committee, the panel that will hold confirmation hearings on Obama’s nominee.

The president’s nomination is expected over the next few weeks.

Obama’s discussions with candidates for the high court have not been formal interviews, the administration official emphasized, speaking on condition of anonymity to protect the privacy of Obama’s deliberations. The official would not say whether the conversations have been held in person or by phone.

Obama is choosing a successor to Justice John Paul Stevens, who is retiring this summer after nearly 35 years on the court. Obama’s choice will leave his imprint long after he leaves office, as justices have lifetime tenure and enormous power to shape American life with their interpretations of the Constitution.

Obama’s review process has become more concentrated since he wrapped up a nuclear security summit of world leaders in Washington last week, although he is juggling as all presidents do, including his stepped-up campaign for a new law to regulate Wall Street behavior.

The president plans to start calling senators of both parties on the Judiciary Committee to gather their opinions about the court vacancy. That kind of political outreach can help him get a sense of the fight ahead; he did the same last year before nominating Sonia Sotomayor to replace another retiring justice, David Souter.

Obama is considering about 10 people for the court.

Among them are federal appeals court judges Diane Wood, Merrick Garland and Sidney Thomas, former Georgia Chief Justice Leah Ward Sears, Solicitor General Elena Kagan, Michigan Gov. Jennifer Granholm, Homeland Security Secretary Janet Napolitano, and Harvard Law School dean Martha Minow.