WATCH: Cruz calls Trump a 'sniveling coward' over wife tweet

( - The war of words between Donald Trump and Ted Cruz heated up Thursday as Cruz called Trump a “sniveling coward” after the billionaire tweeted an attack on the Texas senator’s wife.

“I don’t get angry often, but you mess with my wife,you mess with my kids, that’ll do it everytime.” Cruz said at a Wisconsin factory. “Donald, you’re a sniveling coward, leave Heidi the hell alone.”

The fiery reaction from Cruz comes after Trump retweeted an image late Wednesday from a supporter which contrasted a picture of Trump’s wife Melania alongside an unflattering image of Cruz’s wife Heidi, with the caption “a picture is worth a thousand words.”

When asked if he would support Trump if he became the nominee, Cruz said “I’m going to beat him for the nomination…Donald Trump is not going to be the nominee.”