Hillary is also at this time not a democratic candidate for president

If you missed it, the following facts apply.

1. Sanders has said that he is contemplating running as a democrat. Discussing his potential candidacy as a democrat is not outside the TOS. If he said outright that he had rejected that path, you could have a claim although as we know this is not pure. There have been discussions throughout history on trying to pull independents and republicans to the democratic party.

2. When Hillary runs, she could also run as an independant. She was once a registered member of the Republican party. Can you state with certainty until she runs as a democrat that she will not run as either an independant or republican.

Of course we do not really expect HRC to run as either a Republican or an independant. However, I wished to point out that your argument against discussing Sanders candidacy as a democrat would only be valid if you were also arguing that noone could discuss or advocate for Hillary to run for president because she is not a democratic candidate for president.

The TOS if it applies at all applies would only seem to apply to actual candidates with declared parties in their candidacy not discussions of desire for people who they would like to run. Otherwise, you could have not have any political discussions of candidates before their declarations. I have not seen statements that they would only support Sanders if he ran as an independant (although I could imagine someone posting that as part of a discussion). The posts seem to only urge him to run or not run and discuss whether they would vote for him.