washington u.s. treasury secretary steve mnuchin say plan big tax cut u.s. history due release late wednesday white house would cut business tax rate 15 percent include small businesses go big tax cut large tax reform history country mnuchin say news forum washington say fundamental agreement president donald trump administration congress goals tax reform detail would work separately house representatives speaker paul ryan say see sneak preview plan like lot put us page agreement 80 percent 20 percent ballpark ryan say mnuchin say business tax rate 15 percent trump tax plan