It is true, as Jimmy Quinn says, that intervening in elections abroad to promote democracy and human rights is different from, and better than, intervening in them to promote the interests of an autocratic and gangsterish government. But there’s also a question of national self-respect.
When other countries spy on us, we don’t seriously treat it as a shocking moral outrage. But we do punish it and take action to prevent its recurrence, and we don’t let the knowledge that we do it too stop us.
If another country bombed us, only a tiny fringe of Americans would say that we should relax about it because we’ve bombed other countries too. Most people would ignore that line of argument, and they’d be right.