The tape’s political effect is muted because everyone is dug in. Trump’s foes have already concluded that he’s unfit for office and needs to be removed forthwith; Trump’s supporters (most of them) acknowledge his serious shortcomings but think it’s more important to focus on his agenda and accomplishments. It’s difficult to find a further personal peccadillo that can budge anyone from these trench lines, since there’s no real contest over his character to begin with.
The irony is that Trump’s detractors hate him so much that they have created, perhaps, an impossibly high standard for his misconduct.
It’s not damning enough for them that the Russians interfered in our election and Trump is dismissive of it; Trump has to be a quasi-Russian agent who actively colluded with the Kremlin, perhaps going back decades. It’s not damning enough that Trump had affairs with a porn star and Playmate; he has to have committed some serious criminal offense in the course of covering his tracks.