If it's opinion based, then it's trickier to pin it down to being either truth or lie, but if the opinion goes against the opinion of knowledgeable experts then

If it's opinion based, then it's trickier to pin it down to being either truth or lie, but if the opinion goes against the opinion of knowledgeable experts then I think that should be communicated too so that people can make a more informed judgement. When the lies are about matters of fact, then politicians should be held to a similar standard as advertisers i.e. not allowed to just push completely false narratives without some consequence. Unfortunately it appears that the U.S. administration is frequently lying about factual issues such as with the NASA mission.