Restate the question, please. The commerce clause is far older than the 14th and they actually don’t work tougher to expand federal power. The 14th incorporates the restrictions on the federal government contained in the Bill of Rights to the state governments. It’s Due Process and Equal Protection clauses have been used to expand federal power. But that is a different, if parallel, development from the elastic interpretation of what is “necessary and proper” under the Commerce Clause. (The Necessary and Proper Clause is often called the Elastic Clause because it stretches so often and doesn’t mean anything like what normal English speakers think of when they use the term “necessary.”)