An Executive Order CAN can be nullified if it's proven unconstitutional.
If the US Supreme Court declares an Executive Order (Presidential action) unconstitutional, it is checking the Executive Branch.
The Executive branch decides is a treaty is unconstitutional
the executive branch
The Judicial Branch can declare a Presidential Order (called an Executive Order) unconstitutional. While the US Supreme Court is the final arbiter of constitutionality, even US District Courts can overturn an Executive Order, as was the case with President Obama's moratorium on deep water drilling in the Gulf. The lower court's decision may be appealed all the way to the Supreme Court, but in this instance it wasn't.
The Judicial Branch can declare an Executive Order (a Presidential Order) unconstitutional if it is presented to the court as part of a case or controversy.While the US Supreme Court is the final arbiter of constitutionality, even US District Courts can overturn an Executive Order, as was the case with President Obama's moratorium on deep water drilling in the Gulf. The lower court's decision may be appealed all the way to the Supreme Court, but in this instance it wasn't.
It can declare acts of the president unconstitutional
If he abuses his power just like the past few presidents YES... It's called an Executive Order (which, in my opinion, is unconstitutional)
The executive branch is responsible for implementing and enforcing laws. However, the supreme court has the power to deem any action unconstitutional or unlawful, and prevent or undo those actions.
It can declare acts of the president unconstitutional
Judicial
Judicial