* Bush says undocumented immigrants can stay, but only as residents
* Undocumented must return home to apply for citizenship
* Advocates for more legal immigration
By David Adams
MIAMI, March 5 (Reuters) - In a new book published on Tuesday former Florida Governor Jeb Bush seeks to claim the middle ground on the hot topic of immigration reform, proposing residency for undocumented immigrants but tough conditions for citizenship.
Bush's plan advocates against allowing undocumented immigrants to obtain citizenship unless they return to their country of origin first, according to an advance copy of the book "Immigration Wars: Forging an American Solution."
"It is absolutely vital to the integrity of our immigration system that actions have consequences - in this case, that those who have violated the laws can remain but cannot obtain the cherished fruits of citizenship," he writes in the book which was co-authored with conservative attorney Clint Bolick.
"To do otherwise would signal once again that people who circumvent the system can still obtain the full benefits of American citizenship. It must be a basic prerequisite for citizenship to respect the rule of law."
Bush's position surprised some immigration advocates, as well as fellow Republicans, who had expected him to come out with more lenient proposals.
"I'm surprised and very disappointed," said Cheryl Little, director of Americans for Immigrant Justice, a Miami-based immigrant advocacy group. "It was my impression that Governor Bush has long been a champion of fair and humane immigration reform."
Instead of citizenship, Bush, 60, argues that immigrants who came to the United States illegally could apply for permanent legal residency, as long as they pay a fine and perform community service, as well as paying back taxes and learning English.
Under the Bush plan, undocumented immigrants would be able earn U.S. citizenship only if they return to their home countries and apply through regular legal channels. They would also face a three- or 10-year bar depending on how long they had been in the United States illegally.
Bush makes an exception for young undocumented immigrants, known as DREAMers, who were brought to the United States by their parents before the age of 18. Under his plan they would be given residency with the ability to apply for citizenship after five years.
Bush's position puts him slightly to the right of Republican Senator Marco Rubio from Miami, one of eight senators pushing for bipartisan immigration reform. Rubio has advocated giving immigrants a more direct pathway to citizenship without being forced to leave the United States, albeit also with strict conditions.
Speaking to reporters in Washington on Monday, Rubio said he had received a copy of the book last week from his longtime political mentor but had not had time to read it.
"I just exchanged emails with him congratulating him on the book and I haven't had a chance to talk to him in depth on why he's adopted this new position," Rubio said.
"To permanently say you are going to have millions of people who can never apply for citizenship, hasn't really worked well for other countries that have tried it," Rubio added.
Bush has never previously endorsed a specific package of proposals on immigration reform, though he has on occasion sounded favorable to more generous terms for creating a pathway to citizenship.
Bush has long stressed the need for the Republican party to reach out to immigrants generally and the fast-growing number of Hispanics and Asians in particular, "not just for the good of the country but for the party's survival."
Bush's position has not changed, said his spokesperson, Jaryn Emhof. "The book does not prohibit individuals here illegally from ever earning citizenship," she said.
Emhof noted a study published last month by the Pew Hispanic Center that found only 36 percent of Mexicans eligible for citizenship had availed themselves of that option. Mexican immigrants account for 6.1 million - about 55 percent - of the estimated 11.1 million in the United States as of 2011, it pointed out.
"Not all immigrants want citizenship. They want to come out of the shadows, want to live here legally, and they want respect," she said.
While immigration advocates may not be happy with some of his proposals, Bush spends much of the 270-page book published by Simon & Schuster lauding immigrants.
The main purpose of the book, write the authors, is to lay out an economic case for an improved system of legal immigration, pointing out that the current U.S. birth rate is not keeping pace with the demands of the Social Security system due to a declining worker-to-beneficiary ratio.
Far from being a burden, immigrants fuel economic growth, business entrepreneurship and cultural vibrancy, they argue.
Bush uses the book's preface to explain his own personal ties to the immigration issue, describing how he fell in love "at first sight" when he met his Mexican wife of 38 years.
"Thanks to my wife I became bicultural and bilingual, and my life is better for it," he writes. (Additional reporting by Richard Cowan in Washington; Editing by Lisa Shumaker)