Last fall's presidential election was blessedly free of the turmoil that marked the 2000 vote count, but mainly because it was a blowout. In a tighter race, a candidate who loses the popular vote can still win the presidency by cobbling together the right states. The National Popular Vote initiative would cure that; states representing a majority of the Electoral College would pledge their support to whoever wins the popular vote nationwide. Last week, Washington state became the fifth state to commit to the proposal, which almost passed last year in Massachusetts. (Both chambers of the Legislature approved it, but it failed to clear the final hurdle before the end of the session.) This year, the Commonwealth should adopt it.