President Donald Trump on Friday used a Rose Garden luncheon held in honor of Mother’s Day to ramble about his paving over of the world famous spot, to bash his predecessor repeatedly and to boast about extrajudicial killings of suspected drug smugglers as he addressed a group of Gold Star moms. Trump opened his speech to the audience of military parents, White House staffers and other guests by discussing the merits of the stone patio he used to pave over the grass in the Rose Garden, which was designed during the Kennedy Administration, claiming that it was impossible for anyone to walk on the grass because the White House “was built on a wetland and the grass was always soaking wet,” and suggesting that his Agriculture secretary could not properly deliver remarks because she was too concerned with damage to her high heels.…