Donald Trump pledged in his “Contract with the American Voter” at Gettysburg on Saturday that he would take five specific actions on “Day One” (Inauguration Day, which is Jan. 20, 2017) “to restore security and the constitutional rule of law.”

They are:

“First, cancel every unconstitutional executive action, memorandum, and order issued by President Obama.”

This bold move could cover numerous policy areas, both foreign and domestic. Many of Obama’s unconstitutional actions have been invalidated by the Supreme Court, such as his recess appointments when the U.S. Senate was not in recess, which the justices unanimously ruled against in NLRB v. Noel Canning.

Others are found in federal laws—such as Obamacare’s individual mandate, wrongly upheld 5-4 in NFIB v. Sebelius by declaring it a tax—and therefore can only be rescinded by Congress’ changing the statute.

But some are executive actions that are still in force. The clearest example is Obama’s executive amnesty for illegal aliens, which a federal appeals court invalidated on statutory grounds, and which was indefinitely put on ice when the Supreme Court deadlocked on the case in U.S. v. Texas. But the DAPA program—like its predecessor DACA (which applied to the children)—also violates the Constitution’s Take Care Clause because the president rewrote federal law, which the Constitution assigns exclusively to Congress.

Another is Obama’s “transgender directive.” For years the Far Left has tried to push legislation like ENDA (the Employment Non-Discrimination Act), which would amend iconic laws like the Civil Rights Act of 1964 to make sexual orientation and gender identity specially protected classes in this nation on the same level as race.

The Obama administration has redefined the term “sex” in Title VII and Title IX—which make it illegal for employers and schools to discriminate on the basis of sex—to include gender identity. This redefinition allows male high school students and even adults (such as teachers) to share bathrooms, locker rooms, and showers with high school girls at the same time girls are using that facility, so long as the male says he identifies as a female on that day.

Half the states of the nation have sued in federal court and won a major court victory, because it is clear that Congress’ using the word “sex” refers to biological sex. (The Justice Department is currently appealing that ruling.) Obama’s order to the contrary is an unconstitutional violation of the separation of powers, because only Congress can make laws.

“Second, begin the process of selecting a replacement for Justice Scalia … from one of the 20 judges on my list, who will uphold and defend the Constitution of the United States.”

Only a very small handful of lawyers in America could ever fill the shoes of Antonin Scalia, either in terms of being a reliable adherent of Scalia’s originalist judicial philosophy, or in terms of matching Scalia’s towering intellect.

Trump’s initial list of 11 potential Supreme Court justices includes several such judges, and his second list of 10 includes a couple more, if you count Sen. Mike Lee (R-UT). Top conservative leaders still hope to see a couple more of the greatest conservative minds of this generation added to the list. Of these, their top choice is Solicitor General Paul Clement, perhaps Scalia’s most brilliant and accomplished former law clerk—having repeatedly saved both the Second Amendment and religious liberty before the Supreme Court, and having led the fight against Obamacare—and thus a fitting heir to Scalia’s seat on the High Court.

Between these choices and the possible addition of a superstar like Clement, Trump could restore the Court to where it stood before Scalia’s passing.

The last three promises concern immigration:

Third, cancel all federal funding for Sanctuary Cities.

Fourth, begin moving the more than two million criminal illegal immigrants from the country and cancel visas to foreign countries that won’t take them back.

Fifth, suspend immigration from terror-prone regions where vetting cannot safely occur. All vetting of people coming into our country will be considered “extreme vetting.”

All these could trigger legal challenges from liberals, but Trump’s actions on each front are fully constitutional—under the Constitution’s Spending Clause, Naturalization Clause, Commander-in-Chief Clause, and Receive Ambassadors Clause—as well as fully consistent with federal law.

Each of these actions can be achieved by a legal use of executive orders—which every president since George Washington has used to implement federal law and exercise constitutional powers—on his first day in office, if the American people entrust Donald Trump with the presidency.

Ken Klukowski is senior legal editor for Breitbart News. Follow him on Twitter @kenklukowski.