There is an immediate political reason why it is important to deny that the IRS abuses had any political effect: If they did have a political effect, then the question becomes whether that effect was sufficient to change the outcome of the 2012 election. That is to say, unless Plouffe’s denial is true, the very legitimacy of the president’s re-election is in doubt.
Yet even if we assume Obama would have won re-election without any IRS shenanigans, that is no excuse for the wrongful conduct. Richard Nixon carried 49 states and nearly 61% of the total popular vote in 1972. No one thinks the burglary at the Watergate office complex was necessary for his re-election. Yet even a landslide does not mitigate an abuse of power.