user: Question: What was the GTP winning team in the round in Portland during which Jack Baldwin become part of the GTU winning team? 
Columns: ['Rnd', 'Circuit', 'GTP Winning Team', 'GTO Winning Team', 'GTU Winning Team', 'Results']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Daytona', '#00 Kreepy Krauly Racing', '#4 Stratagraph Inc.', '#76 Malibu Grand Prix', 'Results']
SQL:

assistant: SELECT "GTP Winning Team" FROM "Table" WHERE "Circuit" = 'Portland' AND "GTU Winning Team" = 'Jack Baldwin';