The Internal Revenue Service, already under fire after officials disclosed that the agency targeted conservative groups, faces increased scrutiny because of an inspector general’s report that it spent about $50 million to hold at least 220 conferences for employees between 2010 and 2012.The report by the Treasury Department’s inspector general about conference spending is set to be released Tuesday. The department issued a statement Sunday saying the administration “has already taken aggressive and dramatic action to reduce conference spending.” The White House and the agency were on the defensive before the report on conference spending. Agency officials and the Obama...