GOP's Pledge To America

Consider this pledge for Congress: "Require every bill to be certified as constitutional before it is voted on."

And now consider this "analysis" from the MSN web site:

Not so harmless, however, is the promise to require every bill to be certified as constitutional before it is voted on. We have a mechanism for assessing the constitutionality of legislation, which is the independent judiciary. An extraconstitutional attempt to limit the powers of Congress is dangerous even as a mere suggestion, and it constitutes an encroachment on the judiciary. 

Is it an "encroachment on the judiciary" for Congress to consider, for example, whether proposed legislation exceeds its own power under the Commerce Clause? Even if Congress takes a more narrow view of its own power?