How do you know when a politician is lying?

Here is a CNN story on a difference between what Obama promised when promoting passage of the ACA and what he said recently. I particularly like the bite where Obama says, "We will keep this promise."  Here is the video released by the Obama folks which they said is a 4-minute summary of the plan. Note the first point.

I am not confident that what he said recently is accurate. My understanding is that individuals will lose plans that do not meet the standards specified in the ACA even if the plans have not changed since the passage of the bill. Here is a story about cancellations.

FYI: When his or her lips are moving.