KARL ROVE: Here's what's behind George W. Bush's beef with Ted Cruz and Donald Trump

Former President George W. Bush made news on Tuesday when Politico reported that he had recently taken a shot at a Republican presidential candidate, Sen. Ted Cruz (R-Texas).

Bush reportedly shocked a room by suddenly saying he doesn’t “like” Cruz, whom he called “opportunistic” for pandering to real-estate mogul Donald Trump.

Bush’s spokesman didn’t back off the report, either. His rep told Politico that Cruz, a former Bush staffer, is not the most “serious rival” of his brother, former Florida Gov. Jeb Bush (R), in the 2016 GOP primary.

Karl Rove, who was George W. Bush’s top political adviser, explained the animosity Tuesday during a Fox News interview. He cited Cruz’s criticism of Supreme Court Justice John Roberts after his pro-Obamacare rulings despite staunchly supporting his nomination to the court.

“I do know that President Bush has expressed some — on a number of occasions — a little bit of astonishment as to the attacks that Ted made on him. For example, [he] went out of his way to attack his appointment of John Roberts,” Rove recalled.

“Yet at the time of the appointment of John Roberts, Ted Cruz was a personal friend of John Roberts, wrote a strongly positive piece about him … said that both John Roberts and the man who appointed him, George W. Bush, were strong, dependable conservatives.”

Rove also confirmed Bush’s spokesman’s statement that dismissed Cruz’s potential to defeat Jeb Bush in the presidential race.

“That’s true for a fact. He’s told me who he thinks his biggest rival is but I’m not saying who it is,” Rove said. “It’s just not Ted Cruz.”

Karl rove fox newsFox News/screengrabKarl Rove, right, on Fox News.

For his part, Cruz took the high road when Politico asked his campaign about George W. Bush’s broadside, which he suggested was a sign of his campaign’s strength.

“I have great respect for George W. Bush, and was proud to work on his 2000 campaign and in his administration,” Cruz told Politico. “It’s no surprise that President Bush is supporting his brother and attacking the candidates he believes pose a threat to his campaign. I have no intention of reciprocating.”

Rove went on to describe George W. Bush as baffled by Trump’s success in the Republican primary.

“President Bush is mystified, I think that’s the right word to say, that Donald Trump — I mean, here’s a guy who called for the impeachment of President George W. Bush, criticised Nancy Pelosi in 2007 for not doing enough to remove the Republican president from office,” Rove said.

“And so, yeah, I think there’s a little bit of mystification in Dallas as to Donald Trump’s conservative credentials,” he continued, railing against Trump for offence after offence. “He repeats statements that are simply not true. … That is an absolute lie. … That is simply not true.”

Watch below:

NOW WATCH: Cop pulls a clever move to save a man from suicide

NOW WATCH: Briefing videos

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.