(CNN) All politicians exaggerate. All politicians hedge facts to suit their arguments. But practically no politician has ever stretched the truth to -- and past -- the point of breaking more than President Donald Trump.

According to The Washington Post's irreplaceable Fact Checker blog , Trump has said more than 3,200 partially or totally inaccurate things in his first 497 days in office. That's 6.5 mistruths a day. Every day.

The stat in the Fact Checker post that really took my breath away was this: In his campaign rally for Rep. Marsha Blackburn's Tennessee Senate campaign on Tuesday night, Trump said 35 things that weren't true. (I went through that speech line by line .)

There's a tendency -- especially after the campaign Trump ran -- to roll your eyes about his exaggerations, half-truths and, in some cases, lies. That's just Trump being Trump! He just says stuff! You can't take him literally!

Count me in the group -- and the Toronto Star's Washington correspondent Daniel Dale is its president -- who sees Trump's assault on truth as the single most important and potentially damaging element of his presidency. Trump's casual relationship with the truth isn't a side story of his administration. It is THE story of his administration, its one defining feature.

Past presidents have, of course, said things that wound up not being entirely accurate. As conservatives in my Twitter feed like to remind me, then-President Barack Obama's promise that "if you like your health insurance, you can keep it" wound up not being true under the Affordable Care Act. ( PolitiFact dubbed that claim the "lie of the year" in 2013.

The difference is that in almost every case, the presidents weren't purposely lying. In most cases, they were shaping the existing facts to their benefit -- in some instances seizing on the best case scenario even if it didn't look likely to pan out. In others, they simply misstated a fact or facts -- which is something short of a lie because it lacks the intent necessary to be termed a lie.

In virtually every case, once a president has been proved wrong, he stops saying the wrong thing -- whether because of a commitment to intellectual rigor or simply a desire not to be pummeled for not telling the truth by the media (and the other party).

Again, Trump represents a clean break from that way of doing things. Trump has repeated 122 false claims at least three times during his presidency. According to the Fact Checker , Trump has falsely claimed that the border wall is being built 19 times in just the last three months.

Far from shrinking from falsehoods, Trump revels in them. Fact checks are proof, to Trump and his supporters, of the bias of the "fake news" media. Of course, the media says Trump is saying things that aren't true -- they hate him! This isn't really a story about falsehoods, it's a story about media bias!

Which, of course, it isn't. It's a story about facts. And Trump's unwillingness to adhere to them.

The long-term impact of the idea of "alternative facts" or that we are each entitled to our own facts is truly terrifying. If we can't, as a society, agree on a set of facts, the idea of reasoned discussion and -- gasp -- progress beyond our current stalemated debate is out the window. If everything is relative to your political leanings, then there is no truth -- only your perception of it.

Make no mistake: We are headed in that direction today. And while Donald Trump didn't create the idea of two sets of facts for our two national parties, he has maximized that divide for political gain.

The degradation of the idea of truth may not seem relevant when you are filling up your car with gas or when more than 200,000 new jobs were created last month. But it has massively important consequences for who we are as a society and, as importantly, who we will be.