Jonah Goldberg at NRO rings up a fantastic subjunctive tu quoque:
Yes, it’s extremely unlikely he ordered the IRS to discriminate against tea-party. . . . And his outrage now — however convenient — is appreciated. But when people he views as his “enemies” complained about a politicized IRS, what did he do? Nothing.
Imagine for a moment if black civil-rights organizations, gay groups, or teachers’ unions loudly complained to members of Congress and the press that the IRS was discriminating against them. How long would it take for the White House to investigate? Answer honestly: Minutes? Hours?
The overall form of subjunctive tu quoque is not that you have actual inconsistent behavior or double standards, but that you would have them. You just know it! Of course, this form of tu quoque requires, for the subjunctive to be accepted, that the audience think the President is a hypocrite and an employer of double standards. So, often, the subjuctive form of the tu quoque isn’t an argument from hypocrisy, but one to it.
**A later addition to the post 5/21/2013**
For other discussions of subjunctive tu quoque, see Colin’s original post HERE, and John’s got a lengthy discussion HERE, and we three co-wrote a paper that appeared in INQUIRY about a year back, which I’ve posted on my Academia.edu page HERE. For cases that tu quoque arguments are regularly relevant, see one of my recent posts on it HERE, and my essay in Informal Logic HERE.