From the NYT article:
Mr. Trump had wanted Ms. Conway to have a spokeswoman role in the administration. She declined that role and publicly discussed working with an outside political group backing the president, even as she held out for a West Wing position that would have a title on par with those of Mr. Priebus and Stephen K. Bannon, the chief strategist....So... "counselor" or "counsellor" — which is it? I know there's this rigorous American trend — when adding suffixes — to strip out double letters whenever possible.
Mr. Trump is deeply fond of Ms. Conway, whose job as counselor will give her frequent access to the president. A “Trump whisperer” during the campaign who was particularly adept at explaining his appeal to voters, Ms. Conway will serve as one of the chief protectors of Mr. Trump’s political brand.
For example, "shipping" will probably never become "shiping," "worshipping" is becoming "worshiping." You can see the evolution occurring — occuring?! — right now in the NYT, which has 2 articles on the same event.
In one, written by NYT reporters is "Member Charged in Arson of Black Church With ‘Vote Trump’ Scrawled on Side,"* there is the line "After the fire, Hopewell congregants began worshiping at the First Baptist Church of Greenville, a predominantly white congregation." In the other, an AP story about the same event — "Fire Marshal: Politics Unlikely Motive in 'Vote Trump' Arson" — you find the same sentence, but with the other spelling: "After the fire, Hopewell congregants began worshipping in a chapel at predominantly white First Baptist Church of Greenville. "
I found myself naturally writing "counsellor," but the Grammarist tells me that's not the "American spelling," though it is the preferred — prefered?!! — spelling everywhere else. Am I not an American?
* Yeah, it wasn't a pro-Trumper who spray-painted "Vote Trump" on a black church. Big surprise.