Miller probably needs to pay some more taxes plus penalties. But this is too complex an issue, and too GOP a district, and too late, for this seat to really be in play, even in this toxic anti-GOP year.
If I'm not mistaken, Miller has no opponent on the ballot, so there's no way the seat could be in play. This would be a very daunting seat for Dems in any event. Bush took 62.1% in this district, which makes it a bit more GOP than the Doolittle seat (61.3%), which has far more reason of this type to be competitive, but certainly isn't.