> The alternative to the monarchy in Saudi Arabia is not a liberal democracy, but rule by the clerics, who are even worse and, from my understanding, have the support of the populace
That excuse has long been used to justify support of brutal, oppressive regimes. It often leads to 'blowback', resulting in brutal, oppressive, anti-Western successors, such as in Iran.
Also, nobody can say how things would turn out, and whether the result is better or worse is a judgment for the Saudi people to make. If given the power in a democracy, they can always elect someone else.