The money is the means of Robert Mueller's investigation into Trump

It should shock absolutely no one that special counsel Robert Mueller is focusing in on President Trump's money flows. Mueller is specifically interested in the Trump organization's receipt of payments from foreign individuals connected to foreign governments.

Russia, of course, stands out here.

As ABC News reported on Friday, one particular area in Mueller's focus is the payments Trump received towards his inauguration costs. That said, I have been confident since late last year that Mueller has at least two other focus areas related to foreign money and the Trump Organization. The most relevant concern here is the question of Trump benefiting from Russian actors who retain close links to President Vladimir Putin.

Yet Mueller's interest in accounting records has a special significance for the special counsel in that it allows him to attempt to paint a forensic picture of a quid pro quo relationship between the Russians and the Trump Organization.

This isn't a fishing trip in the darkness. As one source told me, "This allows Mueller to gather evidence for trial proceedings without needing to publicize sensitive intelligence community sources and methods." The source added that this is an especially operative concern in that some of the investigative material Mueller has acquired was provided from foreign intelligence partners. Those partners demand that their information remains highly classified and out of the public domain.