2016 GOP candidate: If Republicans can't stand up to Trump, how will they stand up to ISIS?

The Twitter beef between Donald Trump and former New York Gov. George Pataki is escalating to new, rather absurd heights.

This week, Pataki repeatedly denounced and called on his Republican primary rivals to condemn Trump's comments asserting that many Mexican immigrants are "rapists" and drug runners.

In a tweet on Thursday, Pataki took the fight a step further, suggesting that if the Republican field can't stand up to Trump, they'll never be able to deal with the extremist group calling itself the Islamic State (also known as ISIS or ISIL).

In his presidential announcement speech last month, Trump railed against Mexican immigrants.

"When Mexico sends its people, they're not sending their best; they're not sending you," Trump said then, according to a transcript. "They're sending people that have lots of problems, and they're bringing those problems with us. They're bringing drugs. They're bringing crime. They're rapists. And some, I assume, are good people."

Earlier this week, Pataki told Business Insider that Trump was "disrespectful," and urged his fellow candidates to denounce the reality television star.

Trump fired back at Pataki on Wednesday in a slew of tweets, saying that the former New York governor "couldn't be elected dog catcher."

Trump has faced severe backlash for his comments. NBC, Univision, and Macy's have all announced that they will sever their business ties with Trump following the real-estate mogul's comments.

Pataki isn't the first candidate to invoke ISIS to project strength. 

In February, Wisconsin Gov. Scott Walker said that his record fighting unions showed that he could take on difficult challenges abroad like fighting ISIS. 

"If I can take on 100,000 protestors, I can do the same across the globe," Walker said.