By David Schwartz

PHOENIX (Reuters) - Arizona Governor Jan Brewer, a Republican who clashed with the Obama administration over immigration and once wagged her finger at the president on an airport tarmac, said on Wednesday she would not run for re-election, ending speculation about whether she would seek a third term.

Arizona governors are limited to serving two terms at the state's helm. But Brewer, 69, rose from the position of Arizona secretary of state to take over mid-term in 2009 from Janet Napolitano, a Democrat who left to head the U.S. Department of Homeland Security.

There had been speculation she could seek another four years in office on the grounds she had not served two complete terms.

Brewer, announcing her decision at a school once attended by her sons in the Phoenix suburb of Glendale, said she felt it was time to "pass the torch of leadership."

"So, after completing this term in office, I will be doing just that," she said.

Brewer made national news in April 2010 when she signed into law a bill to crack down on illegal immigration in the southwestern U.S. state that shares a border with Mexico.

The Obama administration challenged the law, the first of its kind in the nation, saying the federal government had jurisdiction over immigration enforcement. The U.S. Supreme Court in 2012 partially struck down the law, including a provision requiring immigrants to carry paperwork at all times.

But the high court upheld the law's most controversial aspect, a requirement that police officers check the immigration status of people they stop, even for minor offenses.


In 2012, Brewer was seen wagging her finger at President Barack Obama when she greeted him at the airport during a Phoenix visit.

But she has sometimes gone against conservative elements in her own party. Last year, she infuriated many conservatives when she signed a law to expand Medicaid as part of Obama's signature domestic achievement, the Affordable Care Act.

Last month, under mounting pressure from business and gay rights groups, she vetoed a measure that would have allowed business owners to use their religious beliefs as grounds for refusing to serve gay couples and others.

Republican U.S. Senator John McCain of Arizona praised her.

"First entering public service as a mother concerned about the workings of her local school board, Governor Brewer has served with distinction at every level of state and local government over the last three decades," he said in a statement.

Brewer, after taking over as governor from Napolitano in 2009, was elected to a full term the following year. Had she decided to seek another term, Brewer would have had to run for re-election in November.

Among those vying for the Republican nomination for governor are Secretary of State Ken Bennett, state Treasurer Doug Ducey and city of Mesa Mayor Scott Smith. Former state Board of Regents member Fred DuVal is running to be the Democratic nominee.

Some legal experts had suggested that one reading of the Arizona constitution's provision for term limits might have allowed Brewer to run again.

(Reporting by David Schwartz; Writing by Alex Dobuzinskis; Editing by Cynthia Johnston and Bernadette Baum)