A power that is vested in the president is subject to approval by the Senate. legally guaranteed by the Supreme Court. legally guaranteed by the Constitution. subject to approval by the House.

The correct answer is legally guaranteed by the Constitution

According to the constitution, if people elect a president he will have powers that are enumerated in the constitution and that are not related to the house or the senate, since those are the legislative branch, or the supreme court since it's the judicial branch. The president is the head of the executive branch so his powers are his own while in accordance with the constitution.

A power that is vested in the president is "legally guaranteed by the Constitution," although it should be noted that the Constitution can be amended, meaning this power can end.