http://www.washingtonpost.com/wp-dyn/content/article/2010/03/15/AR2010031503742_pf.html
Article 1 Section 7 of the US Constitution -
Oh and there may already be a SCOTUS ruling on this. When they overturned the line-item veto, Justice Stevens wrote:
Article 1 Section 7 of the US Constitution -
But in all such Cases the Votes of both Houses shall be determined by Yeas and Nays, and the Names of the Persons voting for and against the Bill shall be entered on the Journal of each House respectively.
Oh and there may already be a SCOTUS ruling on this. When they overturned the line-item veto, Justice Stevens wrote:
If one paragraph of that text had been omitted at any one of those three stages, Public Law 10533 would not have been validly enacted. [Emphasis added] If the Line Item Veto Act were valid, it would authorize the President to create a different law - one whose text was not voted on by either House of Congress or presented to the President for signature.
Something that might be known as 'Public Law 10533 as modified by the President' may or may not be desirable, but it is surely not a document that may 'become a law' pursuant to the procedures designed by the Framers of Article I, Section 7, of the Constitution.