The President (Executive Branch) has the power to appoint US Supreme Court justices and other (Article III ) federal judges. subject to approval by the Senate. He can and does choose judges who subscribe to his own legal philosophy and so can possibly shape future court opinions. The judges serve for life and their stance on future cases is hard to predict in many cases.
The president can also grant pardons for federal offenses
One is the fact that the judicial branch needs the executive branch to enforce its decisions. As an example, when the Supreme Court ruled that segregation in public schools was unconstitutional in Brown v. Bd. of Education of Topeka, it took the President's ordering the National Guard out to make some states abide by the ruling. The Judicial Branch has no way to enforce its decisions without the executive's co-operation.. Another is the fact that it is the executive branch that nominates the judges in the first place. As a practical matter, presidents nominate persons who share the same political beliefs they do. This has the effect of creating (or trying to create) a judicial branch that will interpret the Constitution the way that that president would like. Trouble is, once a Supreme Court Justice is confirmed, nothing can be done to force him or her to rule in a particular way. They are appointed with lifetime tenure on good behavior and their salaries cannot be diminished while they are in office.. And as to salaries, nothing says a president has to include raises for them in any budget he proposes.
The Executive branch gets to choose candidates for federal judgeships, including Supreme Court Justices. The President also has the power to pardon people convicted of federal offenses, Since the President controls the Department of Justice, he has some leeway in how laws are enforced.
