The three clues below have something in common that is hinted at by the fourth clue. Can you determine what it is?

1. BETA DECAY

2. PLACED A BET

3. HEATED BLANKET

4. Engender public controversy 

Answer to Clue 4:

STIR DEBATE

 

Each phrase conceals the consecutive, but scrambled (stirred) letters for DEBATE:

 

1. BETA DEcay

2. placED A BET

3. hEATED Blanket

 

Credit: Evan Kalish