I'm talking about using them at the start of the sentence, meaning "so" or
"therefore".

「今日は暇だ」 「だから、映画でも見に行こう?」/「なので、映画でも見に行こう?」

I'm assuming that the difference is simply the same as the difference when
they are used as a conjunction in the middle. That is to say, なので is slightly
more objective and polite.
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2018-03-28T16:13:02.463
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2018-03-28T16:13:02.463
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question
meaning
What is the difference between だから　and なので