> When you have a two-party system, you get binary outcomes - ie. divisiveness.
The two-party system problem seems to be a consequence of "first-past-the-post" voting.
For example, some posters in reddit's /r/conservative were very insistent in attacking libertarian voters, pinning on them the responsibility of Trump's election loss. Their rationale was that they felt libertarian voters threw their vote away by voting on a candidate who had no chances of winning, thus robbing their candidate of support that they felt he would otherwise have if no libertarian candidate ran for president.
Consequently, they argued that the only rational approach to the elections would be if all like-minded voters concentrated their vote on not-so-good-but-popular somewhat like-minded candidate so that they could have at least a chance of electing someone who, even though might not be the best candidate in the voter's opinion, was closer to support some of their views.
The divisiveness is a consequence of the primary system, not the two-party system. The primary system is very new, only here since 1972, but the fact is that 1) the power to nominate candidates should have never been handed to the voters, and 2) now that it has been, it is impossible to revoke. The "strategic" aspect of nominating a candidate closer to the center, to capture as much of the political spectrum as possible, is impossible to coordinate with individual voters but very easy to execute by party insiders.
Without primaries, Barack Obama would have never been President but Donald Trump wouldn't have been either.
When you have a two-party system, you get binary outcomes - ie. divisiveness.
It doesn't even make sense to expect something else.