That said Trump is going to see how this turns out, but a judge at this level has no authority to change federal law or limit the presidents power.
That is not entirely accurate. Judge Robart is a judge in the US District Court for the Western District of Washington which lacks the ability to declare the OE unconstitutional, but can order a TRO (temporary restraining order) if, in his opinion, the plaintiffs (the states of Washington and Minnesota) were likely to succeed at a later date; people in those states could suffer irreparable harm if the ban continued; and blocking the president's order was in the public interest.
What this does is force the issue into the 9th Circuit Court of Appeals (the most liberal of the Circuit Courts of Appeals), to be heard by a three judge panel made up of judges from that Court. Even then the
en banc Court, made up of 11 or the 29 Judges, can either confirm or reverse the decision of the District Court.
And even then it is not over. It will go to the US Supreme Court and, in view of the present make up of the Supreme Court, the immigration pause will probably be confirmed. (Wrongly, in my opinion - but that is based on my dislike of Executive Orders that violate the Separation of Powers clauses in the United States Constitution, Article 1 Section I which gives Congress "legislative powers herein granted" and Section 9 lists actions that are prohibited for Congress. The clause in Article II, unfortunately, places no limits on the Executive branch, simply stating that, "The Executive Power shall be vested in a President of the United States of America.")
So, as of now, the pause has been paused. This may, or may not, result in less stringent vetting of immigrants from the 7 countries known to support or harbor terrorists. However, even though the pause has been paused, INS can still strengthen the vetting process to help insure no terrorists enter the country.
Frankly, in my opinion, there is less danger from refugees fleeing the failed states of their homelands than there is from the home grown variety such as MSA and other domestic groups.
It is going to be a very interesting couple of years until we get this all sorted out.