No, false forms of Christianity are incompatible with conservative goverment.
With Real Christianity (Roman Catholic Catechism, I'm Catholic, so sue me.):
1) Life imprisonment is completely okey-dokey.
2) If he's REALLY bad and you know for an absolute fact he's guilty (Osama Bin Ladin, Beltway Snipers, etc.)
a) Pray for him.
b) Tie him into 'Old Sparky'
c) Forgive him.
d) Pull the switch
e) Pray for the dearly departed.
Assuming that the guilty party's identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor.
If, however, non-lethal means are sufficient to defend and protect people's safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and more in conformity with the dignity of the human person.
Today, in fact, as a consequence of the possibilities which the state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm—without definitively taking away from him the possibility of redeeming himself—the cases in which the execution of the offender is an absolute necessity "are very rare, if not practically non-existent."
I'm not saying I disagree with you, but the Church seems to.
Roman governors did not convert to Christianity until after they resigned from their office, because it was part of their official duty to sign death warrants. Government was considered incompatible with Christian belief during the pre-Constantine period.
The Catholic Church is supposed to be based on historic precendent, but that's what the Pope taught in the 2nd century AD.