In 2008, Obama was elected and both houses were Democratic. When he leaves office the presidency and both houses will be Republican. May I suggest a great deal of the blame is due to – wait for it – a comatose and complacent Democratic Party that continually moves to the right to attract Republican moderates rather than strongly support its traditional working class base. This strategy has been a disaster.
Trump at least pretended to care about the struggling lower 50% and yelled loudly he will help them. And they listened and responded.
Sure, Comey interfered, and there were two third parties. However the Libertarians probably took more from Trump than from Clinton. And the Green Party was basically non existent.
Clinton did substantially worse in multiple states than Obama. She managed to lose Wisconsin (which had voted Democratic for President since 1988), Michigan (since 1992), and Pennsylvania (since 1992.) This was a disaster, and mostly self-inflicted by the Democratic Party.