Yes it is, which is why the inability of Cruz’s supporters to admit their candidate played unprincipled dirty politics on a caucus night is so stunning.
They attack anyone who points out the truth - really bizarre behavior.
Get it over yourself. Since when is it unprincipled politics to use a news source? What I find unprincipled is the lack of any healthy debate in favor of name calling. Trump needs to show me he can withstand some criticism and rise above the fray, as do the rest of the bunch!
But unfortunately he likes to name call and sling mud at the first hint of any slight or sign of disrespect or even at the perception of the same.