It's entirely possible that by 2016, Clark County will be able to sway a statewide election for a Democrat regardless what the rest of the state does.Last week's split election results showed a fine line between the success of President Obama and the failure of Senate candidate Shelly Berkley.Berkley came within 12,000 votes of defeating Sen. Dean Heller by winning only Clark County.There was a time in Nevada when a politician had to have a majority in at least Clark and Washoe counties to win the state.It's long been true that if every Nevada voter outside of those two counties …