All eyes will be on the Supreme Court in the months ahead as the Justices decide to tackle a landmark case involving the separation of powers.

The Obama administration has asked the high court to take a case in which a federal appeals court declared that President Obama’s immigration plan was unconstitutional and unlawful. Now, the Supreme Court has agreed to weigh in.

I reported last fall that the U.S. Court of Appeals for the Fifth Circuit concluded that President Obama’s actions constituted an unlawful overreach – an unconstitutional power play.  The appeals court determined that President Obama’s actions were “‘manifestly contrary’” to congressionally enacted immigration law.

In other words, the appeals court correctly concluded that Congress makes the laws – not the president.

We have been involved in this issue from the very start. During the legal course of this case, we’ve represented 113 Members of Congress—25 U.S. Senators and 88 members of the House of Representatives. We also represented nearly 220,000 Americans in its briefs.

And in 2014, I testified before the House Judiciary Committee – providing detailed evidence as to why President Obama’s actions violate the separation of powers.

The arguments that succeeded in blocking the implementation of President Obama’s action then are the very arguments that should succeed at the Supreme Court.

The constitutional system is simple.  Congress makes the laws.  The president enforces the laws.  And the courts interpret the laws.

President Obama simply can’t use his unelected bureaucratic agencies to rewrite our nation’s laws when Congress chooses not to do so themselves. This responsibility resides with Congress, not the president.

We will be filing an amicus brief at the Supreme Court – again, representing members of Congress and thousands of Americans.

Our position from the beginning has been very clear: President Obama is not a king and impatient presidents don’t get to change the law. This executive overreach is both unlawful and unconstitutional.

We are hopeful that the Supreme Court will uphold the appeals court decision – and put a stop to the impermissible overreach that has become the hallmark of this president.

Jay Sekulow is Chief Counsel of the American Center for Law and Justice (ACLJ), which focuses on constitutional law. He’s a New York Times bestselling author. Jay's latest book “Undemocratic: Rogue, Reckless and Renegade: How the Government is Stealing Democracy One Agency at a Time” (Feb 2) is available now. He hosts "Jay Sekulow Live"-- a daily radio show which is broadcast on more than 850 stations nationwide as well as Sirius/XM satellite radio. Follow him on Twitter @JaySekulow.