>>There's a long-standing idea in the US that a president or governor who has a convincing win has a mandate for his or her policies while one who wins a close election does not.
The problem with ideas, is that they're like opinions: everybody can have their own and they can change like the wind.
Which is why it's worth expressing good ideas in rules with a defined democratic process to change those rules, or governments, or Presidents. Of course the US does have such rules to grant mandate to Senate, Congress and the Cabinet led by President. That august process just happened again, granting mandate to the Republicans across the board. At some point, doesn't unrest and protest against lawful mandate meet the definition of sedition?
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
