The chairman of the Senate Judiciary Committee served notice Wednesday that he intends to question Harriet Miers about the Bush administration’s policy of detaining terror suspects at Guantanamo Bay, injecting new uncertainty into a Supreme Court nomination already in doubt.

In a letter to Miers, who is White House counsel, Sen. Arlen Specter also said he would ask what assurances she could offer that she would be independent, if confirmed, “and not give President Bush any special deference on any matter involving him that might come before the Court.”