Complex sentence: That is, the ability of the people to choose officials in government is checked by not allowing them to elect Supreme Court justices--however in reality, such justices are appointed by the popularly elected president, and approved by the popularly-elected Senate.
Split into simpler sentences: That is, the ability of the people to choose officials in government is checked by not allowing them to elect Supreme Court justices. Such justices are appointed by the popularly elected president, and approved by the popularly-elected Senate.