Why didn't Turbo Tax Deluxe port over my long term capital loss from my 2016 return?

The carryover should have transferred from your previous year's return.  It's hard to say why it didn't; however, you can enter the amount easily.

To include your long-term capital loss carryover on your 2017 return, please follow these steps:

1. Click on Federal > Wages & Income
2. In the Investment Income section, click on the Start/Update box next Capital Loss Carryover.  [See Screenshot #1, below.]
3. On the screen, Did you have investment losses you couldn't claim in 2016? click the blue Yes box.
4. Click the appropriate radio button on the screen, Do you know your capital loss carryover amounts?  [Screenshot #2]
5. Enter your figures on the next screen, Tell us your capital loss carryover amounts from 2016.  [Screenshot #3]