WASHINGTON - Sour grapes. That's how Donald Trump's closest advisers see Democrats' complaints that Moscow hacked their private emails this election season in a bid to sow discord among their supporters and sway the election toward Republicans.

The pushback comes ahead of the Electoral College vote, which is expected to make official Trump's election win.

Trump's incoming chief of staff, Reince Priebus, says there's no evidence that Russian interference in the election changed the outcome.

But for Democrats it was a personal attack and a threat to democracy.

Foreign policy experts say part of Russia's calculation was likely a desire for payback for years of U.S. criticism of its own elections and to paint America as a flawed champion of democracy - potentially weakening it on the world stage.