If it’s just a matter of Senate rules, the Senate is empowered to effectively do anything they want under the Constitution.
The real issue is that once you set a new precedent, there’s no going back. The Democrats invoked the nuclear option for Federal judges below the level of the Supreme
Court, so the Republicans took that one step further.
Both parties understand that once they use the nuclear option or just adopt new rules at the beginning of the new session of Congress to disarm and disempower the minority because they have the majority, that that same precedent can be used against them the next time it is politically expedient to do so when they are in the minority position.
So the politics matter, because at the end of the day Senators still have to get along well enough with each other to get some Bills passed, most importantly the appropriations bills, not the biggest flashiest Acts of Congress they can muster and nobody or at least very few in the Senate truly want the filibuster gone.
If it were only about the rules, you are correct. If it’s about the politics, you might be correct on a long enough time scale, but it’s irrelevant in the short to medium term. Right now we’re in a holding pattern on the cloture rules because of promises of tick for tack escalation between both parties. It’s not as if one party is going to loosen them for themselves for one session of Congress and be able to reasonably expect that they will be tightened up to their benefit by their opponents once they’re a minority in the next session.
The real issue is that once you set a new precedent, there’s no going back. The Democrats invoked the nuclear option for Federal judges below the level of the Supreme Court, so the Republicans took that one step further.
Both parties understand that once they use the nuclear option or just adopt new rules at the beginning of the new session of Congress to disarm and disempower the minority because they have the majority, that that same precedent can be used against them the next time it is politically expedient to do so when they are in the minority position.
So the politics matter, because at the end of the day Senators still have to get along well enough with each other to get some Bills passed, most importantly the appropriations bills, not the biggest flashiest Acts of Congress they can muster and nobody or at least very few in the Senate truly want the filibuster gone.