Republican presidential candidate and former Texas Governor Rick Perry formally announces his candidacy for the 2016 Republican nomination for president at an event in Addison, Texas, June 4, 2015. [Photo/Agencies]

A grand jury indicted him on abuse of power and coercion after he publicly threatened - then carried out - a veto of state funding for public corruption prosecutors. That followed the Democratic head of the unit rebuffing Perry's calls to resign after her arrest for drunken driving.

Perry says the case against him is purely political, but he's been unable to get it dismissed on constitutional grounds - and may eventually have to pause campaigning to appear in court.

In his speech, Perry savaged the Obama administration for Iraq's decline after US combat troops left, for what he sees as a flawed nuclear deal being negotiated with Iran and for an insecure border with Mexico.

"A lot of candidates will say the right things," Perry said. "We need a president who has done the right things."

According to Perry: "We're at the end of an era of failed leadership."

Texas' white-hot job growth was fueled by an oil-and-gas boom, but Perry said his keeping taxes low, restricting regulation and curbing civil litigation awards helped. Perry also distributed millions in state funds, hoping to lure top job creators to Texas - sometimes with few new jobs to show for it.

Perry is playing up his military experience in a Republican field that has few veterans.