Why did anticommunist Harry Truman veto the McCarran$-$Walter Act?

a$.$

The anticommunist measures targeting immigrants did not go far enough for Truman.

b$.$

The McCarran$-$Walter Act closely mirrored the Committee on Immigration$$s report, Whom Shall We Welcome, an investigation commissioned by Truman$$s political enemies.

c$.$

Truman had become alarmed at the excesses of the anticommunist crusade.

d$.$

Truman did not actually veto the act, preferring to propose an alternative bill.

e$.$

The bill did not adequately address how to respond to undocumented immigrants.