Nothing hypothetical about it. An American citizen - seized on American soil - has already been detained and tortured for 3 years while the government fought tooth-and-nail to deny him the right to appear in court.
http://www.cato.org/dailys/08-21-03.html
Oh, yeah - you'll love this part... When the government avoided a likely defeat at the Supreme Court by grudgingly bringing a case against him, their charges include none of the serious allegations they had spent those 3 years using to justify their detainment of him.
The Act is just a legal framework for letting Bush get away with it again in the future.
Now, I'll wait for your explanation of how Padilla didn't deserve to be heard in court because "he's a terrorist". 
So in support of your claim that the Military Commissions Act of
2006 applies to American citizens, you cite someone who was detained three years BEFORE the Act was passed? BUZZZZZZ! Try again.

Don't dig a deeper hole dude. If you're being intellectually honest you will admit the plain language of the Act applies to aliens, who are explicitly defined to exclude American citizens.
"ALIEN--The term 'alien' means a person who is not a citizen of the United States."
Section 948a(3).
"PURPOSE--This chapter establishes procedures governing the use of military commissions to try
alien unlawful enemy combatants engaged in hostilities against the United States for violations of the law of war and other offenses triable by military commission."
Section 948b(a) (emphasis added).
You still haven't explained how the preceding language of the Act applies to American citizens.
[clock ticking]