The President duty to prevent Congress passing any legislation that he feels is uncomstitutional, Congress has the authority to over turn the President's veto with the concurrence of two thirds of the members of both houses.
Any time a bill is passed by Congress that the President believes is unconstitutional he has a duty to veto the proposed legislation.
If two thirds of members of both the House and Senate disagee they have the power to over ride the President's veto.
Instead of requiring a simple majority to pass a new law if two thirds of members of both Houses would were required very few bills that violate the Comstitution would be approved.
Out of the over 2,500 bills submitted to the President only 112 were over tirned by Congress. Requiring two thirds of the members of both houses to pass a law would greatly reduce the numner of unconstititional laws and statutes each year.
Had James Buvhanan had vetoed the Fugitive Slave Act in 1857 it is possible that the Civil War could have been avoided and 600,000 lives could have been saved.
The President has the power to veto bills that he believes are unconstututional and Congress has the authority to over ride the Presidents veto with the concurrece of two thirds of the members of both the House and Senate..
In the histpry of the veto there have been a total of 2,593 bills that have been vetoed, but only 4 percent of the vetoes have been over ruled by Congress,
I believe that Congress should have the power to veto Supreme Court decisions with the support of two thirds of both the Senate and House of Representativrs.