A memo circulating among at least half a dozen advisers to former President Donald J. Trump recommends that if he is elected, he bypass traditional background checks by law enforcement officials and immediately grant security clearances to a large number of his appointees after being sworn in, according to three people briefed on the matter.The proposal is being promoted by a small group including Boris Epshteyn, a top legal adviser to Mr. Trump who was influential in its development, according to the three people.It is not clear whether Mr. Trump has seen the proposal or whether he is inclined to...