If he didn't understand the importance of Gitmo, though most did, then he should not have made those repeated promises.
How else can we judge a person but by their word? And that's just what a promise is.
To dismiss a promise as unimportant, and make excuses for not keeping it, is lowering standards to such an extent that any political platforms will become meaningless, and the public will have no one to blame but themselves.
This looking the other way because it was your candidate who lied or misrepresented himself will serve the other party just as well when their candidate lies. No politician will then be held to any standards whatsoever, and the country will suffer further as a result. We should expect honor and dignity from every politician and avoid the idea that it is a team sport. Instead the electorate, and the media, should again focus on what is best for the country.