The 2016 presidential election will go down as one of the most controversial in recent history. In the Republican primary, Donald Trump made sure to hit back at all of his opponents, though many are now coming back to praise him.

Ted on Trump

When Donald Trump first announced his campaign for president back in June 2015, most Americans and members of the media took his candidacy as a joke. However, as time moved on, Trump proved to offer a legit challenge to the Republican nominee, and eventually picked off the 16 other conservatives running for the spot.

Trump went after "low energy" Jeb Bush, and "Little Marco" Rubio, but he saved his best insults for Texas Sen. Ted Cruz. Labeling Cruz "Lyin' Ted," the former host of "The Apprentice" went as far as to promote a story from the National Enquirer that accused the senator of cheating on his wife with five different women. After Trump won the nomination, Cruz eventually backed Trump, but has since come around to become one of the president's strongest supporters. After sending praise for Trump on Twitter on March 9, social media users quickly reacted.

"Our family had dinner w the President & First Lady, who were warm & gracious.," Ted Cruz wrote on Twitter early Thursday morning, before adding, "Catherine brought Joe--her kindergarten class stuffed giraffe!" In response, Twitter users were quick to remind the senator from the Lone Star State of his questionable past with the commander in chief.

Twitter reacts

"This man insulted your wife and said your dad killed a president.

I understand you have to work with him but this is insane," one Twitter user wrote. "Did you share with the kids how Trump called you 'Lyin' Ted' and told people your father killed JFK? Or his insults about grandma?" screenwriter Amy Holden Jones asked in her tweet to the senator. "This is sad. Even for you," singer Mikel Jollett commented.

Actress Rosie O'Donnell also made sure to add her thoughts, as she didn't hold back when it came to Ted Cruz and his relationship with Donald Trump in the past. "R u in an alternate universe - trump shamed ur family in horrific ways - and u let ur daughters near him - like he's santa - #wtf," O'Donnell tweeted. "This is truly creepy Ted Cruz - no memory ? - no moral backbone," O'Donnell wrote in a follow up message on Twitter, before adding "wow what has become of u sir."