US Presidential race: Businesswoman Carly Fiorina and retired neurosurgeon Ben Carson launch bids for Republican nomination

Carson offers a vision of America as a 'place of dreams' where all of its citizens will prosper if freed from the chains of government

Carly Fiorina is a former CEO of Hewlett-Packard, while Ben Carson is a retired pediatric neurosurgeon (Getty/EPA)

The crowded race for the Republican presidential nomination in 2016 was leavened with insurgent energy as two self-described outsiders, Carly Fiorina, a former CEO of Hewlett-Packard, and Ben Carson, a retired pediatric neurosurgeon, formally tossed their hats into the ring.

While Ms Fiorina, 60, made a failed bid for a US Senate seat in California in 2010, Mr Carson has never run for political office. He declared with a staged event in his native Detroit, where he was raised in poverty before rising at meteoric speed in his profession, mostly at Johns Hopkins Hospital in Baltimore.

An African-American, Mr Carson, 63, grabbed the attention of grass-roots conservatives with a speech at the National Prayer Breakfast in 2013 when he tore into the healthcare reform law pushed through Congress by President Barack Obama. And he did with an unamused-looking Mr Obama in the room.

“It’s time for people to rise up and take the government back,” Mr Carson said before an audience of hundreds at the Detroit Music Hall. “The political class won’t like me saying things like that. The political class comes from both parties.” He offered a vision of America as a “place of dreams” where all of its citizens will prosper if freed from the chains of government.

Ms Fiorina confirmed her run in an interview on ABC News, highlighting her experience in the business world and querying the honesty of a certain other woman with eyes on the Oval Office - Democrat Hillary Clinton. “She has not been transparent about a whole set of things that matter,” she said, citing Mrs Clinton’s private email server as Secretary of State and money flows to the Clinton Foundation.

While Mrs Clinton so far has only one declared rival for the Democratic nod – Senator Bernie Sanders, an independent socialist from Vermont – the Republican field could grow to as many as 20 people. Ms Fiorina and Mr Carson joined three already declared hopefuls - Senators Ted Cruz, Marco Rubio and Rand Paul - with Mike Huckabee, a former Arkansas Governor, expected to join the fray on Tuesday.

Early polling have so far shown Ms Fiorina drawing only a tiny sliver of support while Mr Carson has found a more convincing spot midway among those running or expected to run. But both are surely fringe hopes for now with observers seeing Mr Rubio as a far more serious contender alongside two who have not yet declared – former Florida Governor Jeb Bush and Wisconsin Governor Scott Walker.

Mr Carson, meanwhile, has demonstrated a talent for verbal incaution. Earlier this year, he argued that instances of straight men going to prison straight and emerging gay showed that homosexuality was a lifestyle choice. He suggested that same-sex marriage would encourage bestiality and that Obamacare was the “worst thing that has happened in this nation since slavery”.

The business record of Ms Fiorina is likely also to come under early scrutiny. She was ousted by the HP board in 2005 after a merger with the computer company, Compaq, which she had engineered went awry.

Making her announcement, Ms Fiorina said that the US was at a “pivotal point” and it was therefore “totally reasonable to look outside the political class” for the country’s next leader. A cancer survivor whose 35-year-old step-daughter died in 2009 after struggling with substance abuse, Ms Fiorina also released a memoir, ‘Rising to the Challenge: My Leadership Journey’.