Caught: Krugman's Shifting Arguments ( I got a question about this article)

Murphy had this excellent article on the front page but it would seem to me everyone is making it way more complex then it needs to be. (this is probably not the case and I am more then likely missing something)

The way I see it the unemployment rate is always a percentage, so it makes no difference what the number people in the states that you compare. i.e. if you say one state has a 10% unemployment and another has 3% you are not stating which state has the most unemployed people but you are saying which has the highest percentage of the total population that is unemployed. There could be 100 people in a state or 100000000, if you say there is 10% unemployment in both the ratio of unemployed to employed will be the same.

no?

so saying anything about the how the number of people in a state changes the “percentage” of unemployed is just wrong, right off the bat.

or what am I missing.