A Republican state senator considering an independent run for governor has hired a top adviser to the ex-Republican who became Connecticut's independent governor in 1990. Sen. H. Russell Potts Jr., R-Winchester, has signed Thomas J. D'Amore Jr., one-time chairman of the Connecticut Republican Party and former chief of staff to then-Gov. Lowell P. Weicker Jr. In retaining D'Amore, Potts now widely viewed as a moderate -- edges closer to potentially breaking with his party, which he has criticized for what he described yesterday as its "flat-Earth policy."