No, it doesn't "trump the constitution."
Originally Posted by Maromero
So a treaty signed by the President needs to be approved by Congress in a 2/3 majority. If ratified by Congress, does it does become "the law of the land" trumping the Constitution?
A Google search will quickly turn up many sources which explain this. To cite just one example
An especially interesting piece of evidence supporting the conclusion that the Treaty Clause was intended and understood by the Framing and Ratifying Conventions not to authorize the President and Senate, by a treaty, either (a) to override the Constitution, in whole or in part, or (b) to make domestic law (as distinguished from governance of relations with foreign governments), was provided by a statement by Jefferson--presumably reflecting at the time the prevailing opinion among governmental leaders also and especially leaders in Congress--in his 1801 A Manual of Parliamentary Practice. It was written by him as Vice President, while serving as the presiding officer of the Senate. It was reprinted in many editions in the following generations, being incorporated in full in the "Manual" of the Senate and in the "Manual" of the House of Representatives (as to the part applicable to the particular body in each case). Use of his Manual to some extent continues at the present writing. In this guide, Jefferson stated with regard to the Treaty Clause and power:
[Section 52.] "Treaties are legislative acts. A treaty is a law of the land. It differs from other laws only as it must have the consent of a foreign nation, being but a contract with respect to that nation . . . 2. By the general power to make treaties, the Constitution must have intended to comprehend only those objects which are usually regulated by treaty, and cannot be otherwise regulated. 3. It must have meant to except out of these the rights reserved to the States; for surely the President and Senate cannot do by treaty what the whole Government is interdicted from doing in any way." (Emphasis added.)This brief review of even a small part of the pertinent, historical evidence is sufficient to make inescapable the conclusion that the Framing and Ratifying Conventions intended the Treaty Clause to be limited by the Constitution; that in order to be valid a treaty, like any Federal law (Act of Congress), must be in strict conformity to the Constitution, as amended. The pertinent evidence supporting this proposition is so conclusive that not to accept it would mean (to use Jefferson's striking phraseology in another connection) that human reason must be surrendered as a vain and useless faculty, given to bewilder and not to guide us. The United States Supreme Court has repeatedly decided that the foregoing conclusion is correct, that the treaty-power under the Treaty Clause is limited by the Constitution as a whole; and the Court most recently confirmed this, upon full consideration, in the 1957 Reid case. [My emphasis.]
Note that the first sentence of this passage expressly states that treaties not only cannot override the Constitution, they cannot be used to make domestic law: they may only concern relations with foreign governments.
Ratification by Congress doesn't mean that they become domestic law, just that Congress gets a say in whether a given treaty is adopted at all.