Donald Trump already had slammed the president, the Democratic Party and his Republican presidential rivals.

Donald Trump already had slammed the president, the Democratic Party and his Republican presidential rivals.

And don't forget Mexican immigrants, the Chinese and Sen. John McCain for being a prisoner of war

To that fast-growing list he's now added Fox News Channel host Megyn Kelly.

Maybe he should have just left her alone.

The Republican Party has long wrestled with the public perception that it is waging a "war on women" and has struggled to convince more women that it's on their side.

For the outspoken, combative Trump, Kelly would seem to represent a type of person primed to get his goat.

At 44, she is recognized as successful, whip-smart, commanding and, as she demonstrated during Thursday's GOP debate, more than ready to stand up to the 69-year-old billionaire.