Nevada would abolish its caucus system and revert to a primary election for choosing a presidential preference under a bill introduced Monday in the Nevada Senate.Sen. James Settelmeyer, R-Minden, a prime sponsor of Senate Bill 212, said a main goal of the bill is to allow military personnel serving overseas an opportunity to participate in the presidential nomination process.In a caucus, Republicans and Democrats gather at specific sites on one particular day to choose who they want to see on the presidential ticket. There is no early voting or absentee ballots. Last year, Nevada Republicans held their caucus on Feb. …