Lay people cannot be priests unless they are *sacramentally ordained* to be priests.  Terminology and classifications such as "lay state versus clerical state" are negotiable, but sacramental ordination is not negotiable.  See the definition on the sacramental priesthood by the Council of Trent:

http://www.thecounciloftrent.com/ch23.htm

Can you find a masculinity requirement for apostolic succession?   What matters is the sacramental structure of the Church.  Temptation is everywhere, but structures do matter.  Women can be tempted with clericalism as much as men, but having both men and women in the clergy would be a significant deterrent to clericalism, because clericalism is exacerbated by patriarchalism.   Humanly speaking, ghettos become less so when you open them up.  The clerical ghetto is no exception.  We cannot mess around with the sacramental structure of the Church, but we can and should remove artificial gender barriers.  It is time to ordain women as priests!