Best (aka) easiest route from Tacoma to Sequim

Check WSDOT for a construction closure on 97, Blewett Pass right now:

http://www.wsdot.wa.gov/news/2018/09/06/five-day-closure-us-97-over-blewett-pass-culvert-work-starts-sept-9

If you are already on US2, and don't need to go to Tacoma, consider staying on 2, and taking a ferry across - either the Coupville-PT or Edomonds-Kingston. It'll save some driving, though the cost is more. The Narrows bridge only charges toll on the south bound direction.