The speaker describes his feelings when he receives the letter telling him he has been drafted. Initially his feelings are of disbelief, as he can't understand why somebody like him, who he describes as being "too good for this war," should be called up to fight in it. He has always done well at school and college, and he was certainly no "soldier" through his aversion to camping and tents and his difficulties with coping with authority. Note what he says about who should go to fight in this war that he feels such a strong aversion to:

...if they needed fresh bodies, why not draft some back-to-the-stone-age hawk? Or some dumb jingo in his hard hat and Bomb Hanoi button? Or one of LBJ's pretty daughters? Or Westmoreland's whole family--nephews and nieces and baby grandson?

The speaker therefore feels that those who are for the war and support it should be called to fight in it. He, because he is so opposed to the war, believes that he should not be included in that summons, as he is a "liberal." He therefore selects a group of people who are stereotypically associated with the war as being his example of the kind of people who should be summoned to war in his place.