what principle of the constitution allows congress to override a presidential veto
Veto If the Congress overrides the veto by a two-thirds vote in each house, it becomes law without the President's signature. Otherwise, the bill fails to become law unless it is presented to the President again and the President chooses to sign it.[12] Historically, the Congress overrides the Presidential veto 7% of the time.[13]
Jurisdiction stripping Congress may define the jurisdiction of the judiciary through the simultaneous use of two powers.[1] First, Congress holds the power to create (and, implicitly, to define the jurisdiction of) federal courts inferior to the Supreme Court (i.e. Courts of Appeals, District Courts, and various other Article I and Article III tribunals). This court-creating power is granted both in the congressional powers clause (Art. I, ยง 8, Cl. 9) and in the judicial vesting clause (Art. III, ยง 1). Second, Congress has the power to make exceptions to and regulations of the appellate jurisdiction of the Supreme Court. This court-limiting power is granted in the Exceptions Clause (Art. III, ยง 2). By exercising these powers in concert, Congress may effectively eliminate any judicial review of certain federal legislative or executive actions and of certain state actions, or alternatively transfer the judicial review responsibility to state courts by "knocking [federal courts]...out of the game."[1]