But it's getting inseparable. Trump hasn't been accused of having one person in his campaign or inner circle with questionable ties to Russia, but multiple. Considering the improbability to which Flynn found himself on Trump's shortlist, to his hiring after warnings from Obama who fired him, to the fact that it took eighteen days to fire Flynn after Yates warned the Trump administration. There's little evidence Flynn was a solitary, independent actor in Trump's circle with ties to Russia.
Even if the line of questioning doesn't directly pertain to Trump, Flynn's actions and motivations are still being closely watched for their implications about his hiring of and defense by Trump.