Come out swinging

First Example:

Charlie:  Did you watch the political debate last week?

Emilio:  Of course!  It was so shocking; both candidates came out swinging.

Charlie:  That’s an understatement; they were beyond aggressive.

Emilio:  They attacked each other relentlessly.

Meaning: To "come out swinging" comes from the aggressive act of swinging your arms to punch someone or an object to hurt others.  It’s used as an expression to depict someone mounting a verbal attack on someone aggressively.  In this example, Emilio describes the politicians having a debate which probably involved strong accusations, strong/aggressive behavior or language to attack each other.

Second Example:

Sarah:  If Peter doesn’t have a good explanation for leaving me and my family in the middle of dinner, I’m going to come out swinging at him when he arrives.

Michael:  Hey, take it easy.  Don’t be so violent.  I’m sure there’s a rational explanation.  However, that doesn’t give you the right to attack someone physically.

Sarah:  I won’t actually do it, I’m just so angry for his rude behavior.

Michael:  I understand your anger, but saying something like that will confuse people and think you’re violent.

http://languagesystems.edu/