Other than the second half of the verse, the bassline mostly follows the guitar.  I 
there are a few slightly more complex things done here but these are the basic notes:

First half of verse
("I could be wrong...")
e|-------------------------------|
B|-------------------------------|
G|-------------------------------|
D|-------------------------------|
A|---------3-------5-------------|
E|-3-----------------------------|
Second half of verse
("I could be wrong I could be right!  I could be black I could be white!")
e|-------------------------------|
B|-------------------------------|
G|-----0-------------------------|
D|-----------0-------0-----------|
A|-0h2---0h2----0h2-----0h2------|
E|--------------------------3----|
Chorus
("May the road rise with you...")
e|-------------------------------|
B|-------------------------------|
G|-------------------------------|
D|-------------------------------|
A|-0h5-----5-----5---------------|
E|---------------------3---------|
Bridge
("Anger is an energy...")
e|-------------------------------|
B|-------------------------------|
G|-------------------------------|
D|-------------------------------|
A|--2-----2----------------------|
E|-----0-----0----0----0---------|