Bush I backing Clinton is Trump's biggest defection yet

George H.W. Bush is planning to vote for Hillary Clinton. That's not considered major news by most mainstream outlets. But it should be.

The story, first picked up by Politico late Monday night from a Facebook post by Kathleen Kennedy Townsend, the former Maryland lieutenant governor, got almost no play, for example, from the New York Times. It created only a very small flurry of interest on Twitter, at least judging from my feed.

The only previous exceptions after Franklin Roosevelt to the norm that former presidents support their party's nominee were presidents who were aged, one president — Richard Nixon — whose support wasn't wanted, and one instance in which Jimmy Carter failed to endorse Bill Clinton's re-election in 1996.

Now neither former president Bush is supporting the Republican nominee, with the senior Bush actually crossing party lines to vote for Clinton. They're joined by the 2012 Republican nominee, Mitt Romney, meaning that three of five living former Republican presidential nominees have opted not to support their nominee. And there's a long list of important, albeit not quite as prominent, Republicans who won't support Trump, some of whom are supporting Clinton. That's not even counting those who grudgingly support "the Republican nominee" without saying his name, or in some cases without being willing to say he's qualified for the job.

It's extraordinary. The last time anything at all similar happened was in 1972, when many leading Democrats deserted George McGovern. Sure, there are always a handful of cross-party endorsements in every election, but nowhere near this number, and many of them in normal years turn out to be either very conservative Democrats backing Republicans or very liberal Republicans backing Democrats.

It's also the best evidence, from people who follow politics closely and presumably care about both the fate of the Republican Party and of the nation, that Trump really isn't a normal potential president. These stories are the easiest way to show just how different Trump is from a normal nominee — something reporters have struggled to demonstrate.

After all, every presidential candidate lies, as Hillary Clinton famously did about sniper fire on a tarmac once; it's hard to differentiate that from how Trump is unusually untrustworthy. Any candidate can be caught with a knowledge gap or botch a question, as Gary Johnson did about Aleppo and the New York City bombs recently; it's hard to show that Trump is unusually ignorant about politics and world affairs.

And plenty of candidates have made an ugly remark at some point or have been accused of using dog whistles to appeal to hatred, so how to show that the bigotry at the core of Trump's campaign and his political persona are far more serious?

The cold hard fact is that elite Republicans flee from him precisely because of any or all of these four disqualifying attributes — that he can't be trusted, that he doesn't have the information base to do the job, that his business and personal finances are a mess, and that he's running as a bigot.

In other words: Trump is different. He's not a normal candidate. His candidacy is untenable, according to those who have the strongest incentives to get it right.