CREATE TABLE table_13643320_2 (gtp_winning_team VARCHAR2, circuit VARCHAR2, gtu_winning_team VARCHAR2)

What was the GTP winning team in the round in Portland during which Jack Baldwin become part of the GTU winning team?
SELECT gtp_winning_team FROM table_13643320_2 WHERE circuit = "Portland" AND gtu_winning_team = "Jack Baldwin"
SELECT "gtp_winning_team" FROM "table_13643320_2" WHERE "Jack Baldwin" = "gtu_winning_team" AND "Portland" = "circuit"