Richard Blumenthal received numerous draft deferments between 1965 and 1970, before ending up with a cushy assignment in the Marine Reserve. In this way he avoided serving in Vietnam. Yet several times he has outright claimed to have served in Vietnam. On other occasions his own words or the uncorrected words of others have led people to believe that he had served in Vietnam [ref].
Speaking to a Veterans group in March of 2008, Blumenthal told them that "we have learned something important since the days I served in Vietnam". On another occasion he used the phrase "when we returned", placing himself among the brave returning soldiers that risked their lives fighting Communism in Southeast Asia [ref].
Why would Blumenthal practice such a deceit?
The more likely answer is that Blumenthal lied because that's what he does. It's his modus operandi.
You probably have known people like that. People that make up stories about themselves, or lead you to believe something about them that isn't true. I've known some. They are insecure, or trying to hide something, or trying to manipulate you. With them, it's a habit. Sometimes they don't even realize what they are doing. Call them on it and they might apologize and say the right things. But, rest assured, they'll lie again, and again, if they think they can get away with it.
Was Blumenthal's Vietnam lie an aberration? Not likely. Will he say anything he believes will ingratiate himself with voters? Make false promises to get elected? I don't doubt it.
Many people will probably still cast their vote for Blumenthal, accepting his lame excuses and half-hearted apologies as somehow genuine and redemptive. But a vote for Blumenthal would be a vote against integrity, and an affirmation of deceit. The last thing we need in Washington is more politicians with a disregard for truth.