On truth telling. A question for public dialog

With the revelations about Rep. Weiner of New York there has been a lot of talk, much of it moralistic, from other politicians about being truthful.  There has been verbiage about the "public trust", and violations of that trust.  So here is the question.

When a politician - any politician - tells a lie, or even a half truth for the purpose of influencing peoples view of things, or for the purpose of affecting a piece of legislation, is that "as bad", "not as bad" or "worse" than what Rep. Weiner did when he lied about his tweets?

So when Sen Kyle from Arizona, the Senate Minority Whip (the second highest position in the Republican Party leadership in the Senate) lies in public testimony, testimony designed to be factual debate and affecting legislation, legislation that profoundly affects the lives of vulnerable American people, is that less wrong that what Weiner did? (Acknowledging that what Weiner did WAS wrong?).  No, saying you never meant it to be factual is not an excuse, because it is clear that he presented it as factual.

If a liberal politician were to lie about how much a social services program was going to cost, or inflate statistics related to the environment or and particular social issue, in order to gain support for a particular piece of legislation, how would that measure up to what Weiner did?

There is a lot of moralizing going on, a lot of fingers being pointed, but after what study have shown to be the least truthful campaign in US history (2010), where basically EVERYONE lied, and lied about things at the heart of their role as our leaders (according to the study only 10% of what was said was actually clean fact), I wonder.....

I personally find the ongoing lies being put out there by Americas so called leaders more troublesome.  I want to know the truth.  Not the truth as twisted to support an ideology, but the truth.  The truth about what happens to all those tax cuts that go to the rich.  The truth about what happens to people when programs are cut.  The truth about what the economy is really like.  The truth about government waste. 

What do you think?