Whether a summary judgment in a tax lien-foreclosure proceeding constitutes a 'final judgment on the merits' for claim preclusion purposes, barring a later refund suit under the Tucker Act

Whether a summary judgment entered in a 26 U.S.C. § 7403 lienforeclosure proceeding — whose purpose is limited to enforcing a tax hen and where taxpayers cannot bring refund claims, seek monetary relief, or adjudicate tax liability —constitutes a “final judgment on the merits ” for purposes of claim preclusion, thereby barring a later refund suit under the Tucker Act, 28 U.S.C. § 1491. Whether applying claim preclusion to bar a taxpayer ’s refund suit violates the Due Process Clause where the taxpayer had no full and fair opportunity to litigate the validity of assessments in the § 7403 proceeding, and whether the Federal Circuit ’s rule conflicts with this Court ’s precedent in Williams, Flora, Richards, and Taylor. Whether 26 U.S.C. § 7403 violates the Fifth Amendment ’s guarantee of due process by authorizing the forced sale of a taxpayer ’s home based solely on an irrebuttable presumption that IRS tax liens are valid, while denying the taxpayer any opportunity in the foreclosure proceeding to challenge the legality of the underlying assessment or lien—a deficiency the Treasury Inspector General has recognized deprives taxpayers of the protections available in the seizure process.