Those that claim there is no such thing as absolute truth, just cut the legs out from under their own belief, and exposed themselves as "not the smartest person in the room".
7 Reasons Why Liberals Are Incapable of Understanding The World by John Hawkins
To understand the workings of American politics, you have to understand this fundamental law: Conservatives think liberals are stupid. Liberals think conservatives are evil.</
https://townhall.com/columnists/johnhawkins/2011/08/23/7-reasons-why-liberals-are-incapable-of-understanding-the-world-n1082284