((a)) ** In general** Subject to subsection (b), any alien who—
((1)) has been denied admission, excluded, deported, or removed or has departed the United States while an order of exclusion, deportation, or removal is outstanding, and thereafter
((2)) enters, attempts to enter, or is at any time found in, the United States, unless (A) prior to his reembarkation at a place outside the United States or his application for admission from foreign contiguous territory, the Attorney General has expressly consented to such alien’s reapplying for admission; or (B) with respect to an alien previously denied admission and removed, unless such alien shall establish that he was not required to obtain such advance consent under this chapter or any prior Act,
((b)) ** Criminal penalties for reentry of certain removed aliens** Notwithstanding subsection (a), in the case of any alien described in such subsection—
((1)) whose removal was subsequent to a conviction for commission of three or more misdemeanors involving drugs, crimes against the person, or both, or a felony (other than an aggravated felony), such alien shall be fined under title 18, imprisoned not more than 10 years, or both;
((2)) whose removal was subsequent to a conviction for commission of an aggravated felony, such alien shall be fined under such title, imprisoned not more than 20 years, or both;
((3)) who has been excluded from the United States pursuant to because the alien was excludable under or who has been removed from the United States pursuant to the provisions of subchapter V, and who thereafter, without the permission of the Attorney General, enters the United States, or attempts to do so, shall be fined under title 18 and imprisoned for a period of 10 years, which sentence shall not run concurrently with any other sentence. or
((4)) who was removed from the United States pursuant to who thereafter, without the permission of the Attorney General, enters, attempts to enter, or is at any time found in, the United States (unless the Attorney General has expressly consented to such alien’s reentry) shall be fined under title 18, imprisoned for not more than 10 years, or both.
((c)) ** Reentry of alien deported prior to completion of term of imprisonment** Any alien deported pursuant to section 1252(h)(2) of this title who enters, attempts to enter, or is at any time found in, the United States (unless the Attorney General has expressly consented to such alien’s reentry) shall be incarcerated for the remainder of the sentence of imprisonment which was pending at the time of deportation without any reduction for parole or supervised release. Such alien shall be subject to such other penalties relating to the reentry of deported aliens as may be available under this section or any other provision of law.2
((d)) ** Limitation on collateral attack on underlying deportation order** In a criminal proceeding under this section, an alien may not challenge the validity of the deportation order described in subsection (a)(1) or subsection (b) unless the alien demonstrates that—
((1)) the alien exhausted any administrative remedies that may have been available to seek relief against the order;
((2)) the deportation proceedings at which the order was issued improperly deprived the alien of the opportunity for judicial review; and
((3)) the entry of the order was fundamentally unfair.