TBF, I'm not American, probably why, as I don't know everything that goes on across the pond.
Presidential scholar's like Stephen Skowronek would argue otherwise (precisely that a failed conservative president would set the groundwork for a great liberal era), but I don't think he could have seen the full effects of a conservative media and corporate plutocracy.
Agreed, I have the same concern about the UK as well, though our candidates aren't as right wing as yours, Lab and Con are both different flavours of neoliberal.
Besides, didn't happen after Dubya, and I don't think there's a better definition of "Failed Conservative President" is there? I mean, Iraq on its own is a pretty hefty definition of failure.