SN54HC132: High Impedance State

The inputs always have a high impedance.

When you allow an input to float, its value is undefined, and it might result in unpredictable behaviour. What is predictable is that you will get increase power consumption; see [FAQ] How does a slow or floating input affect a CMOS device?

All inputs (even those of unused gates) must always have a valid logic-level voltage. When in doubt, add pull-up or -down resistors.