WASHINGTON: Hillary and Bill Clinton welcomed the birth of their second grandchild Saturday, gushing that they are “over the moon.” “We are overjoyed to be grandparents again with the arrival of our grandson, Aidan Clinton Mezvinsky, born on Saturday, June 18, 2016,” the presumptive Democratic presidential nominee and her husband, the former president, wrote in a statement. Chelsea, 36, had announced via Twitter a short time earlier that she and husband Marc Mezvinsky had become parents to a baby boy. Hillary Clinton has boasted about being a grandmother as one of the achievements of which she is most proud. “Until it happened to me, I just could not understand the impact,” she was quoted as saying at a campaign event earlier this month. Hillary Clinton is not the only presidential candidate to have welcomed a new grandchild on the campaign trail. Ivanka Trump, the daughter of Clinton’s Republican rival Donald Trump, gave birth to a third child in March. The baby is Trump’s eighth grandchild.