Nothing is “prohibited” by the political doctrine question. This “doctrine” is a legal invention that doesn’t even exist within the Constitution. It’s just an excuse for the Courts to avoid an issue they don’t want to get involved in. Also, when you say they can’t decide what “consitutes proof of eligiblity,” this is an equally ridiculous assertion. The Supreme Court LOVES to make ways to decide metrics.
Let’s look for example at the First Amendment which says Congress shall make no law respecting the establishment of religion. The Supreme Court took it upon itself to INVENT a test for what constitutes the establishment of religion. So here we have a specific phrase from the Constitution being evaluated with arbitrary metrics invented by the Supreme Court.
IOW, this can be done just as well with the eligibility clause, and the SCOTUS has already defined natural-born citizen, so it should be no problem to come up with a standard way to prove how someone meets that definition. After all, they invented standards of proof for other types of citizenship cases. They can do it here too.
Not quite. Article III §2 of the Constitution limits federal court jurisdiction to "cases" and "controversies." neither of which are defined in the Constitution. However, over the last 210 years or so, the SCOTUS has repeatedly ruled that to invoke federal court jurisdiction under the Constitution, the case and controvery must be "justiciable," and that "political questions" are non-judiciable. There are other non-justiciable controversies as well, including moot questions (i.e., whether a person was properly sentenced to death after the sentenced has been carried out); advisory questions (i.e.,asking the court to decide an issue that will not have an immediate impact on the parties, such as the constitutionality of proposed leglislation that has not been enacted into law); and lack of standing (i.e., the person seeking judicial relief has not suffered a harm or consequence that is distinct from the harm or consequence suffered by the public at large).
"Justiciability" and its various subparts is not a recent invention by liberal judges, rather it has been part of our jurisprudence since the earliest days of our Country and is derrived from the English commonlaw. And you are correct in that justiciability is somewhat of a moving target in that judges from both the left and right have used justiciability over the years to side-step cases that they don't want to hear.