It should matter when someone as serious and well-regarded as William Cohen – a Republican, no less – calls out President Trump’s impeachment defense as unmitigated fantasy.

But instead of moving the president’s supporters to take another look at the cold, hard facts, such comments get Cohen labeled a “Never Trumper,” along with other conservatives who have made a clear-eyed assessment of Trump’s behavior and found it a threat to the rule of law.

That’s what happens when feelings and opinion matter more than verifiable facts, and when what team you’re on matters most of all. Americans can disagree on what facts mean and which ones are important. But when we can’t agree on a set of facts when they are right in front of us, and when our leaders use that disagreement to split us, it strikes at the foundation of American democracy.

Cohen was speaking on CNN this week about President Trump’s insistence that Ukraine, and not Russia, interfered in the 2016 election through an extensive, coordinated disinformation campaign, then conspired with Democrats to cover it up.

It is a conspiracy theory with no basis in fact. But it validates both Trump’s 2016 victory and his flimsy impeachment defense, so it gets repeated as gospel by Trump, and by members of Congress. They’ve replaced facts with forcefully told lies, knowing that the Americans whose support they need are not looking for the truth but for a way to defend their side, whatever the broader cost.

So they’ll take the president’s evidence-free claims over the diligent, expert assessment of the U.S. intelligence community, which, following a lengthy investigation, found that Russian President Vladimir Putin ordered his military and intelligence service to engage in a broad campaign to sow distrust and interfere in the 2016 election on Trump’s behalf. The Republican-led Senate Intelligence Committee agreed.

Intelligence officials also say that the president’s theory on Ukraine interference was also first pushed by Russia.

But Maine Sen. Angus King, a member of the Intelligence Committee, said that in all his briefings on the 2016 election, there was never “a hint, a breath, a suggestion, a word that somehow Ukraine was involved.”

Republican Sen. Mitt Romney has said the same, as have Republican senators on the Foreign Relations Committee. So has Fiona Hill, a respected Russia scholar and former senior official in the Trump White House. So have the No. 3 official at Trump’s State Department and the president’s former homeland security adviser.

No one with access to the pertinent information whose political future isn’t wrapped up with Trump’s sees the Ukraine theory as anything but misdirection, aimed at distracting from the facts of the impeachment case. It is as much nonsense as saying the moon is made of cheese.

But since it comes from this president, a good portion of the country accepts it uncritically, and it becomes part of the debate, distorting what should be a sober examination of Trump’s abuses of power.

The president’s ravings on Ukraine fall apart under even the lightest scrutiny. All his conspiracy theories do.

For a strong democracy, that has to matter.