Yes, the truth really does matter, and that is why Trump will not be president. He has been proven to be a liar, and the country needs someone who can actually talk to them and ensure their safety. Once he loses the election, some semblance of sanity will be restored.
The truth matters, but realistically people need to do their research before making decisions about what the truth is based on advertisements, political speeches and campaign promises. Unfortunately, many people repeat inaccuracies that they have heard from what they consider to be reliable sources. That can lead to lie touting, even for people who believe the truth matters.
It doesn't matter at all which idiot becomes our new sockmonkey-in-office. Sensationalist Journalism has killed the truth and we're all choking on the slime they denote to be "news" now. I stopped watching mainstream media news many years ago because, even if the truth were still important, the truth is too deeply buried to be found in the duration of the average american's attention span.
Politicians and their supporters twist the truth to fit their agenda. That's the way it has been and that's how it will continue to be. On the flip side, I think people need to allow their politicians to change their minds as they learn more about an issue. A politician should not be faulted for accepting his mistake and changing his mind.