The Republican at the helm of the Senate’s investigation into Russian interference in the 2016 presidential election backed on Wednesday the assessment by American intelligence agencies that Moscow favored Donald J. Trump in the race, contradicting both the president and fellow Republicans in the House. Senator Richard M. Burr of North Carolina, the chairman of the Senate Intelligence Committee, said in a statement that he saw “no reason to dispute” the intelligence assessment, which was delivered in the final weeks of the Obama administration. Mr. Burr’s statement, while indirect, offered a clear rebuke to Mr. Trump’s most ardent supporters in the Republican Party and in the right-wing news media, who have sought to cast the assessment as the shoddy work of Obama loyalists bitter over Mr. Trump’s election victory. Russia’s only goal, those supporters have insisted, was to sow chaos, and thus it could not have colluded with a campaign it cared little about.
The only logical conclusion, they contend, is the one that Mr. Trump has already reached: The investigation led by Robert S. Mueller III, the special counsel, is a “witch hunt” cooked up by Democrats desperate to undermine a president they detest.
American intelligence officials, including Mr. Trump’s own appointees, who now run the agencies that compiled the assessment, say otherwise. They have repeatedly backed the work of their predecessors and sought to shield Mr. Mueller’s investigation from political attacks.
Asked at a Senate hearing on Wednesday if he stood by earlier statements that the special counsel’s investigation was not a witch hunt, Christopher A. Wray, the F.B.I. director, did not hesitate: “Yes,” he said.