sentence structure with whose elections systems

The following is an excerpt from the New York Times of Nov. 22.

In Michigan, Republicans have zeroed in on Detroit, whose elections system the president has falsely portrayed as so flawed that its entire vote should be thrown out. Lost on no one in those cities is what they have in common: large populations of Black voters.

I cannot make out the part reading "whose elections system the president has falsely portrayed as so flawed that its entire vote should be thrown out."
There seems to be something missing there. Or is this completely OK grammatically?