The Dems have been more successful weeding out their moderates than the GOP has been weeding out theirs.
The Dems are unified under the progressive banner, the GOP is still finger in the air, no backbone, no core beliefs (other than re-election), and still scared of doing anything “conservative” so it’s basically a party of assistant Democrats.
The House spending vote proves it, most Dems approved it but they needed an assist from the assistant Democrats and they got it.
The Dems started infiltrating the GOP years ago.