Background: House Speaker Paul Ryan thinks the only way he can pay for massive tax cuts is through a $1.2 trillion revenue plan known as "border adjustment" that raises taxes on imports and lowers them on exports.

Fighting for border adjustment: The "American Made Coalition," a coalition of more than 25 American businesses. GE is playing a leading role and hosted coalition partners at its D.C. offices recently. Boeing is another big player on this side of the fight. Other industries include manufacturing, high tech, software, medical device production, agriculture, energy production, biopharmaceuticals and information services.

Oh, and Paul Ryan, House GOP leadership, Trump's chief strategist Steve Bannon and (maybe) a lukewarm President Trump.

Fighting against border adjustment: "Americans for Affordable Products." As the AP reports: "More than 100 retailers including Wal-Mart and Target as well as key trade associations are launching a new coalition" aimed at fighting border adjustment. The coalition includes The National Retail Federation, along with the American International Automobile Dealers Association, the National Grocers Association. Walmart is a major hitter in this group and the well-funded Koch network will be supporting the opposition to border adjustment.

Why this matters: It's the biggest fight of the tax season. But, as we have reported, Ryan has his work cut out for him. Especially in the Senate.