There's no smoking gun here. Instead, the Democrats are trying to raise eyebrows by referencing both the pro-Russia talk of Trump's campaign as well as his aides' connections to Russian officials and agendas. Trump's own "hack Clinton" remark, willingness to cozy up to Vladimir Putin and Russia-friendly policies (such as weakening NATO and recognizing the Crimea annexation) are front and center, of course. The letter also references former campaign chair Paul Manafort's role in helping a pro-Russian party gain power in Ukraine, and questions foreign policy adviser Carter Page's involvement in big deals with Gazprom (Russia's state-backed energy giant), among other links.

Whatever you think about the legitimacy of the concerns, there's no guarantee that anything will come out of this. Much like the Republican-led Senate committee on Facebook news filtering, this is as much a political dog and pony show as anything else. It's ultimately casting doubt on Trump's viability as a presidential candidate. While the letter could lead somewhere (the FBI hasn't responded so far), any honest-to-goodness investigation would just be icing on the cake.