Massachusetts has ordered a tire chain to charge Bay State residents a 5 percent sales tax on their purchases in New Hampshire in an unprecedented move that could have huge implications for consumers and other merchants. Town Fair Tire Centers, which is based in Connecticut but has six shops in New Hampshire and 25 in Massachusetts, is fighting back with a lawsuit now before the Massachusetts Supreme Judicial Court that accuses the state of violating the US commerce clause. If Massachusetts prevails in the case, which is likely to be heard next month, it could drive up costs for consumers...