Donald Trump is going to be like no other US president. With his extraordinary public outbursts and his apparent addiction to Twitter, he is continuing to tear up Washington's political playbook. And the denizens of Capitol Hill do not like it one little bit. But the plans by Democrat members to boycott the new president's inauguration this Friday are surely wrong. The trigger for these legislators to announce that they would not attend the event came after Trump attacked a venerable Democrat civil rights campaigner and member of the House of Representatives, John Lewis. The president-elect described Lewis as "All talk, talk, talk - no action or results» and pointed to the high crime rate in Lewis' Congressional district. This led a fellow Democrat Congressman to protest: "When you insult Rep. John Lewis, you insult America". Yet who threw the first insult? Trump was responding to a social media posting from Lewis that said straight out "Trump is not a legitimate president". In the circumstances, Trump's response was mild by his standards. And it could be argued that he had reason to be far angrier. Because it was surely not Trump who insulted America, but Representative Lewis, who chose to decry the democratic choice of American voters. Like many in the liberal establishment who were so sure Hillary Clinton's election was a certainty, Lewis is still in denial at the Trump victory What is being lost here is a key principle that was demonstrated when George W. Bush squeaked his way into the presidency thanks to a very dubious result in Florida. The defeated Al Gore protested and pushed for recounts in certain districts. Had he gone for a statewide recount, Gore might have been victorious. But this was a dispute that could have made its way to the Supreme Court and polarized America. Wiser counsel prevailed. Bush's political opponents rallied round not the man himself, but around the office of the presidency. For all Americans, the presidential seal carries an authority that demands respect, however awful the incumbent may turn out to be. Thus it is not just John Lewis who is insulting America but those politicians who are now boasting that they are not going to be at the inauguration. In seeking to show their contempt for the man Trump, they are actually showing disdain for the office of the presidency and indeed rejecting the choice of US voters. Trump may turn out be everything they fear. Yet, in democracies, the normal rule is that politicians are attacked for what they have done or not done, not for who they are. Trump has not even sat down in the Oval Office and yet many in the liberal establishment are displaying a hatred for their new president every bit as visceral as that felt by white racists when Obama was elected. However, it is not Trump who is actually at risk here. The real danger is further damage to the US political process, which, as Trump's election demonstrated, has already lost the confidence and support of a significant proportion of the electorate.