President Donald Trump’s pick to lead a new Justice Department division dedicated to rooting out fraud says he would pursue prosecutions “without fear or favor,” amid growing questions about how the new unit will operate free of political pressure from a White House that has declared a “war on fraud.” The proposed National Fraud Enforcement Division has raised eyebrows not only because fraud is already prosecuted by the department’s Criminal Division but because the White House has suggested it will have an unusual role in overseeing the new division’s work.