It seems US republican (right-wing or conservative leaning) supporters are more likely than Democrat voters to cling to propaganda or misinformation even after it has been discredited or refuted:
Political scientists Brendan Nyhan and Jason Reifler provided two groups of volunteers with the Bush administration’s prewar claims that Iraq had weapons of mass destruction. One group [...]

Press releases: spin and propaganda
An interesting write up by Gerry Mcgovern questioning the wisdom of placing your own press releases on your website.
Press releases are a form of propaganda. Publishing them on your website shows your customers how you are attempting to spin the media. The Web is where we go because we don’t [...]