He's regarded as one of the most disliked men in Washington.
He's been described by a Speaker of the House of Representatives - a member of his own party - as "a jackass". And former presidential candidate John McCain, senator of Arizona, called him "wacko".
Yet Texas Senator Ted Cruz has taken those insults and worn them as a badge of honour. He believes this shows he's not part of the Washington elite, that he is an insurgent fighting the conservative battle.
READ MORE: Cruz takes down Trump to win Iowa caucuses
After a little over three years in the Senate, he decided to run for president. And after his win in Iowa, and his organisation in southern states, he stands a chance of securing the nomination.
Many outside the US won't know who he is. Many inside will know the name, but very little else.
Rafael Edward Cruz was born in 1970 in Calgary, Canada. While his mother is an American citizen, his father was a Cuban immigrant. His place of birth led Donald Trump to suggest he was ineligible to run for president. The argument in his defence is that he was born an American, via his mother.
The family moved to Texas and in high school there, Ted, as he liked to be known, became interested in public speaking. It was a talent he took to the elite Princeton University, where he won the US national speaker of the year award in 1992.
After graduating with a degree in public policy, Cruz went on to Harvard Law School where he became editor of the university's prestigious Law Review. Harvard professor Alan Dershowitz said "Cruz was off-the-charts brilliant."
He went on to clerk for William Rehnquist - the then chief justice of the US Supreme Court - before moving on to a Washington law firm, where he represented the National Rifle Association and other prominent Republican clients.
Cruz worked on the 2000 presidential campaign of George Bush as a policy advocate and was heavily involved in the drafting of the legal arguments that followed that controversial election.
|Cruz [right] defeated billionaire businessman Donald Trump, the perceived frontrunner in the US state of Iowa [Reuters]
He was appointed to the US Justice Department before being made solicitor general of Texas. He argued before the Supreme Court nine times, saying "there was a concerted effort to seek out and lead conservative fights" with the cases chosen.
In 2012 he ran for the Republican nomination for an open Senate seat in Texas against the better known and much better-funded lieutenant governor of the state.
With the backing of Sarah Palin and prominent conservative names, he won the nomination easily, by 14 points.
It was, the Washington Post said, "the biggest upset of 2012 … a true grassroots victory against very long odds".
In the election against the Democratic contender, he won with more than a million votes to spare.
In his time in Washington, he's become known as a hard-charging, hard-headed conservative. He once delivered a 21-hour speech on the floor of Senate trying to strip funding from the health programme that's become known as "Obamacare".
It led to a 16-day shutdown of the US government. And to plunging approval ratings for Republicans.
When he tried to engineer another shutdown last year, his own party worked against him.
There is an old joke that is regularly resurrected in Washington: "Why do people take an instant dislike to Ted Cruz? It saves time."
It is interesting that not one senator or governor has backed his presidential bid.
And it's thought that the party is deeply worried any Cruz administration would be packed with right-wing activists and people from right-wing think-tanks, given he's much more tied to the ideology than the Republican Party itself.
While he fashions himself as an heir to the Republican totem, Ronald Reagan, if he won the nomination and then the White House, he would be much more conservative than his idol ever was.
He believes Republicans win the White House when they have a real conservative for their candidate. And this time round, he thinks it can only be him. No matter what anyone else says.
Source: Al Jazeera