Backstage at the Republicans' retreat in Philly last week, House Speaker Paul Ryan read over Trump's speech and edited a section on trade. A source familiar says Ryan was helping Trump to "better explain" the border adjustment tax plan.

Ryan's move paid off: Media noted that Trump appeared to be inching closer towards the House GOP tax reform plan.

Why it matters: Ryan is convinced he needs border adjustment — a hike in import taxes and reduction on exports that could raise $1.2 trillion — to pay for major tax cuts. Persuading Trump to become a full-throated supporter of border adjustment is crucial to the Speaker's mission.