coffee, jackk would say that D-s would always save us from a depression – just give them enough years and they eventually will (like FDR and Obama, the latter tried to spend 6 years growing slooowly out of recession), or by saying that things would have been worse otherwise (same Obama claiming that 2008 was “great recession” to justify his approach.
Of course, evaluating policy effect is very complicated. Maybe the best one would be to compare educated forecasts with later performance. In recent history, Biden was expected to do even better than Trump, no inflation risk, then temporary inflation, then inflation. Trump was expected to ruin economy and he did not. Obama was expected to improve economy quickly – and he took 6 years.