What reason does the Republican party have to table the investigation into Palin's alleged mis-use of power?

OK this isn't a question of disrespect towards the republican party, I honestly want to know why they do not want the investigation to go on at this time. It would seem feasible to me that if she hasn't mis-used her power, then she would want her name cleared in time for the election to prove to people that she is who and what she says she is. I know that if I were accused of a crime, and I knew that I hadn't done anything wrong I would want the investigation to get overwith so that I could go on with my daily life without the shadow hanging over me. I would think the longer it drags on the more guiltly she will look. Thank you for your answers.