House Minority Leader Nancy Pelosi introduces House members during the talks with Japanese Prime Minister Shinzo Abe in Tokyo on April 3, 2015.

House Minority Leader Nancy Pelosi's exclusive interview with CNBC's John Harwood will air on Power Lunch in the 1:30 Eastern Time half hour, and you're not going to want to miss it.

Pelosi is at the center of what is becoming the biggest rift ever between Congressional Democrats and the Obama White House. After staying basically silent for months on the Trade Promotion Authority bill, the Democrat leader came out against it just before Friday's key vote. The bill was easily defeated, and now President Obama and Republican supporters of the measure are scrambling to find a Plan B.