we meddle in other country's affairs and elections.  I have no idea what that means, what it is supposed to mean, why it is even a response, and/or if it is supposed to justify anything or provide an excuse for anything.

Maybe someone here who tends to use that "defense" can explain for us.

it means exactly what it says .... The US government has, and does, interfere in the election process in other countries ... many of them of various persuasions, using various means, some subversive, some overt, some covert.  It is understandable, even if the public might not agree and not always placing us in a positive light.

That, imo, should not mean that an attempted interference in our elections by another nation/entity is unimportant or should be ignored.  It is simply putting the entire situation into context and offering a realistic perspective.  It is important to realize that the Russians, and others, have used various techniques to subvert our culture, economy, and elections through the decades, and that this does not present some new and immediate crisis.  It is, of course, very important and deserves an appropriate response.