Learn English – Word for someone who propounds a point despite all basic rational evidence against it

Yesterday Donald Trump tweeted about the upcoming fall 2016 presidential debate calendar between him and Hillary Clinton:

As usual, Hillary & the Dems are trying to rig the debates so 2 are up against major NFL games. Same as last time w/ Bernie. Unacceptable!

Despite the apparent fact that, according to CNN:

In fact, the fall debate schedule was determined almost a year ago by the nonpartisan Commission on Presidential Debates, a private group made up of both Republicans and Democrats.

…

The commission responded to Trump on Saturday afternoon by saying that it "announced the number, dates and sites for the 2016 general election debates in September 2015."
"The CPD did not consult with any political parties or campaigns in making these decisions," the group said.

What CNN says is corroborated by the Commission on Presidential Debates (CPD) website:

The CPD is an independent organization. It is not controlled by any political party or outside organization and it does not endorse, support or oppose political candidates or parties. It receives no funding from the government or any political party, political action committee or candidate.

Commission On Presidential Debates announces sites and dates for 2016 general election debates – Sep 23, 2015

I have to imagine that Trump (or someone in his campaign) knew that Clinton could have had no involvement in choosing the debate schedule (unless there's some heretofore unheard of conspiracy theory). Yet Trump still plainly said Clinton is "trying to rig the debates".

What's a word (or term) for someone who, like Trump in this example, propounds a point despite all basic rational evidence against it?

I was thinking demagogue:

a political leader who seeks support by appealing to popular desires and prejudices rather than by using rational argument.

And while discrediting Clinton is a popular desire, discrediting her on the relatively insignificant issue of debate scheduling is probably not what most people really care about (i.e. it's not popular).

Willful ignorance also might work, but I have a very hard time believing people in Trump's campaign willfully believe that Hillary chose the debate times. Maybe they want their supporters to believe that but no presidential campaign could be that oblivious.

I guess I'm looking for a mix of the two.

^{(Sorry for all the politics here. This debate example really did get me thinking about this question so I used it. For the record I think Trump's criticism of having the debates on football days is legitimate (though perhaps overdue), just his blaming Clinton defies rationality.)}