The Line between True Position and Political Expediency

Election time, for me, always brings to the fore this question:
How much of what politicians say is actual positioning on a question and how much is political posturing and/or expediency?
The constant flip-flopping (as it is commonly referred to) could have two distinct meanings:
1) The person ACTUALLY changed their mind.
2) They are trying to court some portion of the electorate that they need in order to get elected.

In my more cynical moods I tend to think it is always the second option. But I admit that there may be some instances where the first is, in fact, the case.
I imagine that timing is always an important data point. When the change of position comes as a result of public opinion that tends to favor a certain side, it would seem that
for the most part, the politician is being merely expedient.
I have not been able to identify changes of position that came at off times, when it would be more likely to be truly a change of heart.
And for that matter, how does one tell what a politician really thinks?

Thoughts?


"The liberals can understand everything but people who don't understand them."
Lenny Bruce

"The cleverest of all, in my opinion, is the man who calls himself a fool at least once a month."
Dostoevsky