what does "and from behind them came sounds of an awkward row" mean?
Below, Lyndon Johnson had just emerged from the terminal barbershop and was lining up greeters. Usually Lady Bird was at his elbow on such occasions, but she had glimpsed her college roommate in the waiting crowd, and the two women were embracing enthusiastically, leaving him to cope. There was a lot to cope with. Because the ostensible reason for the Presidential call here was a visit to nearby Brooks Aerospace Medical Center, Air Force Secretary Eugene Zuckert had appeared, and he wanted to know where he should stand. Other slots had to be found for Mrs. John Connally, Waggoner Carr, Attorney General of Texas, and an Air Force lieutenant general. Then there were the members of the Vice Presidents own entourage: Cliff Carter, Liz Carpenter, and Marie Fehmer, Lyndon’s young secretary. Behind them, perspiring and craning their necks, stood the twenty-six members of the Chamber of Commerce's red-carpet delegation, and from behind them came sounds of an awkward row. Mayor W. W. McAllister of San Antonio, it developed, had run afoul of the Secret Service.