The president.
Another View: Actually it would be more correct to ask who HEADS the Executive Branch. The individual members of the President's Cabinet, consisting of the chief officers of all the Executive Branch agencies, actually are responsible for 'running' their particular areas of the Executive Branch. The President is more like the Captain of the ship rather than a hands-on day-to-day manager.
The executive branch (the President, cabinet, and regulatory agencies)
The executive branch of the US government is the president.
The purpose of the executive branch of the US government is to enforce laws.
the president
The president heads the executive branch of the US federal government.
The President is chief executive of the Executive Branch of the US government.
The President of the United States heads the executive branch of the US government.
executive branch
President Obama is in the Executive Branch of the government. (Congress is the Legislative Branch, and the Supreme Court is called the Judicial Branch.)
The President of the United States heads the executive branch of the US government.
The executive branch of the US government is headed by the President.
Executive branch (this would be the President of the US)