WASHINGTON — The Justice Department declined on Tuesday to defend a congressional ally of former President Donald J. Trump in a lawsuit accusing them both of inciting supporters at a rally in the hours before the Jan. 6 storming of the Capitol.
Law enforcement officials determined that Representative Mo Brooks, Republican of Alabama, was acting outside the scope of his duties in an incendiary speech just before the attack, according to a court filing. Mr. Brooks had asked the department to certify that he was acting as a government employee during the rally; had it agreed to defend him, he would have been dismissed from the lawsuit and the United States substituted as a defendant.
“The record indicates that Brooks’s appearance at the Jan. 6 rally was campaign activity, and it is no part of the business of the United States to pick sides among candidates in federal elections,” the Justice Department wrote.
“Members of Congress are subject to a…