Speaking at a conference in his hometown of Hope, AR, Huckabee said "We need the kind of change that really could get America from hope to higher ground."
Huckabee, an ordained Baptist pastor, is the third Republican to enter the race this week. Former neurosurgeon Ben Carson and ex-Hewlett-Packard CEO Carly Fiorina also announced plans to run this week. He is the sixth GOP candidate to officially enter the race.
The ex-governor repeatedly acknowledged his humble beginnings. "I don't have a global foundation or a taxpayer-funded paycheck to live off of," he said. "I don't come from a family dynasty, but a working family. I grew up blue collar, not blue blood."
Huckabee vowed to eliminate the Internal Revenue Service, which he referred to as "the biggest bully in America."
"As president I will work to pass the fair tax," he added, saying it wouldn't penalize for their savings and would put an end to government bailouts.
The tax system is not punishing the rich "it's the people working for wages who can't get ahead if the government penalizes them for trying to do better," he said.
"I put America and its workers first. Too many in the political class put Wall Street and Washington elites first. They aren't fighting for American workers," Huckabee wrote in an op-ed in Iowa's Des Moines Register in March.
Current AR Gov. Asa Hutchinson praised his candidacy, calling Huckabee a "proven leader"who is steady on his convictions and values.
Huckabee won the Iowa caucuses in 2008, but eventually lost out on the GOP nomination to Sen. John McCain.
--Reuters contributed to this report.