As Joe notes below, the AP has picked up on something very interesting. Rove may have violated the federal false statements statute if he lied to Bush about his role in Plamegate. (And if he told Bush the truth, then Bush has been concealing evidence in national security investigation.)
(a) Except as otherwise provided in this section, whoever, in any
matter within the jurisdiction of the executive, legislative, or
judicial branch of the Government of the United States, knowingly
and willfully -
(1) falsifies, conceals, or covers up by any trick, scheme, or
device a material fact;
(2) makes any materially false, fictitious, or fraudulent
statement or representation; or
(3) makes or uses any false writing or document knowing the
same to contain any materially false, fictitious, or fraudulent
statement or entry;
shall be fined under this title or imprisoned not more than 5
years, or both.