Who signs proposed bills into federal laws?

The President of the United States is the individual who has the authority to sign proposed bills into law after they have passed both the House of Representatives and the Senate. This process is part of the federal legislative procedure outlined in the U.S. Constitution. Once a bill is approved by both chambers of Congress, it is presented to the President, who can either sign the bill into law, veto it, or choose not to take action, which may result in the bill becoming law under certain circumstances if Congress is in session.

In contrast, the Speaker of the House of Representatives, while a prominent figure in the legislative process, primarily oversees the House and does not have the authority to sign bills into law. Similarly, the Chief Justice of the U.S. Supreme Court's role pertains to the judicial branch and does not include signing legislation. The Majority Leader of the U.S. Senate is influential in guiding legislative priorities and managing Senate proceedings, but like the Speaker, they do not have the power to enact laws directly. Thus, the President is the key figure responsible for the final step in the legislative process at the federal level.