The U.S. Supreme Court has never struck down a constitutional amendment, that is true.
But in other common law countries, like India, whose legal system is very similar to the U.S., have had cases where the Supreme Court struck down a constitutional amendment.
With regard to the Indian case above: while I support the goal of judgement, as the goal of the judgment itself is good, the idea of a Supreme Court overriding a constitutional amendment is quite startling.
The supreme courts of several other countries, including Bangladesh, Pakistan, and Uganda have copied this doctrine.
Who knows when the U.S. Supreme Court will decide to copy this doctrine as well.
Not sure if it is the same in India but in the US there needs to be a supermajority of both houses and the amendment must be ratified by the states. Since the first ten amendments are considered more or less integral to the constitution, I have a hard time believing even this court would consider itself above amendments.
And even then, term limits would be a weird hill to die on, since it would open the door for future courts to strike down constitutional amendments.
