Sam's Vote

John was arguing with Susan. "I will never again to vote for Nancy Pelosi. She has let down the people of our district."
"In all the time she has been in Congress she has always represented us well," Susan countered.
"How about you?" she then asked her sister Joan who was visiting from out of town.
"My Congressman has done okay, I think. I will vote for him again."
After verifying with everyone present that their Representatives to Congress were running for reelection, John then turned to his roommate, Sam. "So, how about you? Are you going to vote for your current Congressman or for someone new?"
"Neither," Sam replied.
"Can't you find someone you want in office?" John asked.
"Oh, I want things to stay just as they are."
"So why don't you vote for your current Congressman?" John asked.
"Because I can't," Sam replied.
"But you're going to vote, aren't you?" John prodded.
"Yes."
"So why can't you vote for your current Congressman?"
Why is Sam unable to vote for his current Congressman?