Are today's presidential candidates, the type to give their last measure of devotion to their country?

They spend all their time campaning, even while holding public office. How can they even compare to others who now hold the same office, who don't neglect their duties to campain for other positions. Their actions prove they have failed in their current duties, so why should they be rewarded. They should finish their term in office in their best ability, then resign to seek other higher office, should they not ?