Republican presidential candidate Ted Cruz attempted to bolster his brand as truly conservative on Tuesday while attempting to paint Donald Trump as a part of the establishment and "Washington cartel" following a bad day for the Texas senator's camp in which he took a major blow from Iowa's governor and Republican firebrand Sarah Palin, with the later recently endorsing Trump.

"It is not a surprise that the establishment is in full panic mode," Cruz told BuzzFeed in an interview on Tuesday. "We predicted from the very beginning that the Washington cartel would fire every tool in its arsenal to prevent a conservative victory in this primary."

Cruz was reacting to the news that Iowa Gov. Terry Branstad called for his defeat in Iowa ealrier on Tuesday. While Branstad has not endorsed a candidate for the 2016 primary season, Cruz saw the slam as direct support for Trump.

"The cartel exists to make deals and to pick winners and losers through cronyism and corporate welfare," the Texas senator told BuzzFeed. "And so it's no surprise that more and more of the establishment is beginning to support Donald Trump. Because Donald has promised to make deals and to continue the cronyism and corporate welfare of Washington. That's what the cartel does. They make deals with Democrats."

Speaking at the Iowa Renewable Fuels Summit on Tuesday, Branstad said it would be a "big mistake" for Iowans to back Cruz, making an economic plea to the voters of the ethanol-rich state and saying that the 2016 hopeful is backed by the oil industry.

"Ted Cruz is ahead right now. What we're trying to do is educate the people in the state of Iowa. He is the biggest opponent of renewable fuels. He actually introduced a bill in 2013 to immediately eliminate the Renewable Fuel Standard. He's heavily financed by Big Oil. So we think once Iowans realize that fact, they might find other things attractive but he could be very damaging to our state," Branstad told reporters, according to the Des Moines Register. "I think it would be a big mistake for Iowa to support him."

Former Alaska governor Sarah Palin endorsed Trump for the Republican nomination on Tuesday -- something the Cruz camp said would be "deeply disappointing."

"I think it would be a blow to Sarah Palin, because Sarah Palin has been a champion of the conservative cause and if she was going to endorse Donald Trump, sadly she would be endorsing someone who's held progressive views all their life on the sanctity of life, on marriage, on partial-birth abortion, he supported [the] TARP bailout - it goes on and on and on," said Rick Tyler, communications director for the Cruz campaign, according to The Hill.

"Donald Trump claims he's changed all those views. But I think if it was Sarah Palin, let me just say I would be deeply disappointed," Tyler added.

There is a tight race in between Trump and Cruz in Iowa, according to RealClear Politics averages of recent polling, which put them in a virtual tie, with Trump ahead of Cruz by just a single percentage point, 27.8 to 26.7 percent. In New Hampshire, Trump has 31 percent, and Cruz is in fourth at 11.3 percent. Trump has 34.5 percent on a national level, with Cruz in second place at 19.3 percent.