As of now I would rate this district as Tilt R / tossup
Two points
On the one hand Trump won this district by double digits in 2016 and even if this district will probably trend D in 2020, Trump will likely win it again by a big margin ; on the other hand this district is very urban/suburban and Oklahoma County is one of the few place in the state where democrats have a true growth potential.
Concerning 2020, it's clear that Horn is vulnerable, republicans have a bunch of good candidates, Horn is not a conservative democrat by most standards, Trump will likely give some coattails effects to the republican candidate, but Horn is still more likely to win than Peterson or Brindisi
This times 1000!
It would not be stunning if within a decade if Oklahoma County begins to vote double digits for the Democrats for local and statewide races and consistently for Democratic presidential candidates. It may end up being the Oklahoma Democratic party.
I disagree with Peterson being dead on arrival that some on the forum think but I am thinking Kendra Horn has a slightly better chance at re-election.