Frankfort, KY – Republican presidential hopefuls Mitt Romney and Newt Gingrich are the only two candidates to officially enter Kentucky's May 22 primary election so far. Gingrich made the ballot Wednesday. Romney filed last week. Ron Paul and Rick Santorum are also expected to meet the state's Tuesday deadline. Because of the timing of Kentucky's primary, presidential nominees typically are decided before Kentucky voters have their say. But the Commonwealth could be important in an especially close race.