No, the reason the "there is always an in-party Senate spoiler" effect (when they have a Senate majority) seems to be more true of Democrats is because it is more true of Democrats, and the reason is that when the two parties in rough balance by popular support (or even rough balance in Presidential electoral prospects, which has the same directional bias as the Senate but of lesser magnitude), the Republican Party has a systematic edge in dominance of states, which translates into a systematic advantage in the Senate, which means that when the Democrats have a Senate majority, it tends to have a decisive segment in red-state Democratic Senators who are unreliable on key priorities.

The issue being discussed in the Senate is not a symmetric issue resulting from near balance in support between the parties.

It’s also because republicans politically punish dissent, while it is more tolerated in the Democratic Party. The consequences of “disloyalty” are higher in the Republican Party.

This might change. After party leadership got 20% of democratic senators to vote for trump’s procedural blank check, the party’s approval rating dropped to 27%.

If it doesn’t change, I suspect the party will split.

I wonder which is better, the totalitarian left, or the totalitarian right?

Since technology has empowered centralized power while providing the tools easily repurposed to poison democracy, I suspect that democracy as we understand it will fail to compete with data driven central planning.

So maybe the question we should be asking is what flavor of total surveillance and centralized control do we want to live under?