I think WA03 will be the upset of the cycle if Perez pulls it off.
And at this point, it looks like she will.
I think WA-3 would break the curse of the President's party winning a seat held by the opposing party AND won by the opposing party in the previous Presidential election. I remember Wasserman mentioning this in 2018 and CA-39 was close but won by the Dems. The last was 1990 I think.
No, that happened in 1998 when Ken Lucas (KY-04) and Ronnie Shows (MS-04) flipped seats that Dole and GOP congressmen won in 1996.