If it means killing citizens with no due process, then it's far too high a price to pay. If I wanted to live in a 'tough-on-drugs' police state, I'd move to Malaysia.
We don't give due-process to enemy combatants. The courts have ruled on this in the past and agree with me. Just imagine giving some German soldiers captured in combat the "right" to an attorney! That is what you are basically asking us to do.
If some US citizen is bringing drugs into our nation, at a time of war, they are aiding and abetting the enemy, the drug-lords. They at that point become traitors to the nation and there is but one penalty for treason.
Believe me, the war on drugs and if we win or lose it, and attacking it in a "due-process" manner like you and the ACLU advocate, is far more important than the important war on terrorism.