By Matt Hardy The Gallagher Premiership could host matches overseas again after Saracens backed the idea of taking English top-flight rugby back to the United States. Premiership clubs have not played a match in the US since 2017, when just 6,000 fans watched Newcastle Falcons take on Saracens in Philadelphia. But Saracens’ new chief executive Mark Thompson has thrown his weight behind the idea and Premiership chiefs are understood to be open to the proposal. “Yes, if the circumstances were right,” he told City A.M. “And if we could see a commercially viable way of audience building and expand…