But what about Trump? The Republican has said so many things about Russia, only to contradict them later. Here is what he's said so far.
Trump knows Putin. Or does he?
Back in May 2014, Trump said he “spoke, indirectly and directly, with President Putin.”
In November 2015, Trump said he “got to know him very well because we were both on '60 Minutes.' We were stablemates, and we did very well that night.”
In the third presidential debate, Trump said: “I don’t know Putin.... I never met Putin. This is not my best friend.”
Russia is hacking the U.S. campaign. Or is it?
Trump has never accepted the Clinton campaign's assertion that hackers controlled by the Kremlin are trying to interfere in the 2016 elections, even after the Obama administration officially accused Russia.
Trump didn't back down in the third presidential debate: “She has no idea whether it’s Russia, China, or anybody else.”
When Clinton interjected that "17 intelligence agencies” had concluded that the Kremlin is behind the cyberattacks on the Democratic National Committee and other political institutions, Trump said, “Hillary, you have no idea. Our country has no idea.”
But his running mate, Indiana Gov. Mike Pence, has contradicted Trump, saying Sunday on “Meet the Press”: “I think there's more and more evidence that implicates Russia.”
The verdict: The GOP ticket has yet to work that out. Russia has denied it.
Russia has outsmarted the United States on missiles. Or has it?
“We're in serious trouble, by the way,” Trump said. “Because we have a country with tremendous numbers of nuclear warheads, 1,800 by the way. Where they they expanded, and we didn’t, 1,800 nuclear warheads.”
Trump mentioned missiles again: "Take a look at the 'start up' they signed,” he said, which seemed to be a reference to the 2011 Strategic Arms Reduction Treaty, or START for short. The deal limited both the United States and Russia to 1,550 strategic nuclear weapons. Both the United States and Russia have far more than 1,800 nuclear warheads, though both have slashed their nuclear arsenals since the Cold War.
While Russia has indeed been modifying its nuclear forces, it's also true Moscow has had a lot of catching up to do: In the economic turmoil that followed the breakup of the Soviet Union, the Russian nuclear arsenal was falling apart.
Far from being left behind, the Pentagon could spend as much as a trillion dollars modernizing the U.S. nuclear arsenal — including $108 billion over the next five years.
The verdict: We may be in trouble for a lot of reasons, but Russian strategic superiority is not one of them.
Trump is not a puppet of Putin. Or is he?
Clinton remarked in the third debate that Putin would “rather have a puppet as president of the United States,” meaning Trump.
“No puppet, no puppet,” Trump shot back.
It's true that Trump has lined up with Moscow on key issues, saying he might accept Russia’s annexation of Crimea and be more open to teaming up with Russia in Syria.
But some Russian policymakers also see Trump as “unpredictable,” someone who could “change the current situation both for the better and for the worse. "Trump is not predictable enough,” according to one senior Russian lawmaker.
What the Kremlin does like to see is a brutal, dirty election campaign that makes Americans question the integrity of their civil institutions and the sanity of their candidates.
Trump doesn't do business in Russia. Or does he?
One reason to wonder about Trump's loyalty to Russia is his possible business interests there. In the second debate, he flatly declared: “I don't deal there. I have no businesses there.” But there's all kinds of evidence, including statements from his advisers and family members, that Trump has done business with Russia.
His son, Donald Trump Jr., said in 2008 that “Russians make up a pretty disproportionate cross-section of a lot of our assets.”
Alan Garten, general counsel of the Trump Organization, told our colleagues in May: “I have no doubt, as a company, I know we’ve looked at deals in Russia. And many of the former Russian republics.”
The verdict: It's really hard to accept that Trump has never done any dealings with Russia. But it's unclear what he's got going on now.
Trump knows nothing of Russia. Or maybe he knows something?
The verdict: It depends on the day.