Your definition of "lying" is so broad as to be useless (and actually in my view harmful) in the real world. I don't think a definition that equates the act of lying about my awesome physique by wearing a shirt with me telling my wife I went fishing yesterday and instead went to see my mistress helps us understand an action or inaction at all - in fact it's harmful to our understanding.
For example, in two distinct areas of my life, I'm prohibited from revealing certain confidences. It's just not a "lie" to adhere to ethical standards and refuse to reveal what I'm obligated to keep confidential. And when you conclude that doing so is a "lie" as you appear to do, you've so mangled the word "lie" so that is diminishes our understanding of human behavior. The "lie" in that circumstance is promising to keep information confidential, then revealing it. But in your definition, I will 'lie" whether or not I reveal the confidential information. The word cannot encompass both acts - maintaining a confidence I promised to keep AND revealing it. Of if the word "lie" does encompass both acts, it's lost all meaning.
As to the OP, I wouldn't ever lie to advance a political agenda, such as it is. Can't see why that would ever be necessary. It would mean that I have, or express, an opinion on some matter that runs contrary to what I KNOW of the facts and evidence. When that has happened in my life, and it's happened many times, I've changed my opinion. It's why I used to consider myself a conservative and voted straight GOP for roughly 20 years, and now do not.