Through cyber warfare attacks and old fashioned espionage, Russia worked to elect Trump. The question now is, why?
There are a couple of likely reasons and the final answer may turn out to be a patchwork of overlapping motivations.
1) Putin did not like Secretary Clinton. As Secretary of State, Clinton exposed the anti-Democratic abuses going in in Russia, and was instrumental in helping set up the sanctions after Russia’s flagrantly illegal annexation of the Crimean penisula.
2) Russia simply wanted to fuck with and destabilize a rival. Over the past 20 years NATO expanded rapidly into eastern Europe. Even if the Russian cyber warfare attacks and espionage were not based on personal animus, Russia still stood to gain by setting Americans against each other and dividing the country by electing a person wholly unqualified and unequipped to be President. Even if the plan failed to elect Trump, they knew a Trump campaign could poison the well of American politics by courting white nationalist. A divided America is good for the Putin regime.
3)They have kompromat on Trump which ensures that he will pursue their goals. Kompromat is short for “compromising material” ( компрометирующий материал) used to exert pressure. Given Trump’s narcissism and history of sexual adventurism, and his many shady business dealings in Russia, it is very likely Putin has something on Trump that Trump does not want disclosed.
So it is one or all of these. Once Russian motives are fully known, it will be time for this country to, at long last, more to the final act of this drama and figure out what this cyber attack on America will cost the perpetrators. And what, if anything, it will cost their American collaborators.