The issue is Trump, not other politicians, or even who among us has not lied.  There has never been known in my lifetime of observing national politics anyone who lies with the ease of Trump.  In his bubble there are neither lies nor truths only happenings which are of benefit to him.  Yes it is based on empirical data, all of which is provided by Trump himself.  We have seen him live in debates, endless nightlong tweets, we have recordings of him boasting of exploits of women, that he grabs them and kisses them at will, we have testimony from his ghostwriter and his biographer both disparaging Trump for his lies, frauds, and phonyness...3500 law suits against him, settled on his fraudulent unitversity.  It is not whether there is 'empirical data', but how much do you require.  Are you as fixed and resolute in your stubborness accepting Trump for what he says he is, as you are in accepting unchanging doctrine and dogma from the first few centuries over what science acclaims to be true.