Bobby Jindal warns of immigrant 'invasion'

Washington: Republican presidential candidate Bobby Jindal, son of immigrant parents from India, says that immigrants who do not adopt American values represent an "invasion".

"Immigration without integration is not immigration; it's invasion, he told ABC Sunday when asked about tough stances against illegal immigration taken by Republican front-runner Donald Trump and other party candidates.

"Look, as a child of immigrants, my parents have never taken this country for granted," said the Louisiana governor who was born in the US three months after his pregnant mother came from India.

"Every single day they are grateful to live in the greatest country in the history of the world. And I think this election is largely about the idea and the idea of America is slipping away in front of us," Jindal said.

"When it comes to immigration policy, what I've experienced and seen is that a smart immigration policy makes our country stronger; a dumb one makes us weaker. We've got a dumb one today," he said.

"Yes, we need to secure our border. Stop talking about it. I think we need to insist that folks who come here come here legally, learn English, adopt our values, roll up our sleeves and get to work."

Pressed on what he meant by "adopt our values," Jindal, who is currently 13th among 17 Republican candidates polling an average of 1.8 percent votes, said that the US must avoid what has happened in some European countries.

"You've got second-, third-generation immigrants that don't consider themselves part of those [European] societies, those cultures. We in our country shouldn't be giving freedoms to people who want to undermine the freedom for other people," he said.

"I think we need to move away from hyphenated Americans," Jindal said taking up his pet theme. We're not African-Americans or Asian-Americans, Indian-Americans, rich or poor Americans: we're all Americans."

"And the reason this is so important: immigration without integration is not immigration; it's invasion. My parents are proud of their Indian heritage, but they came here to be Americans and they love this country. They wanted to raise their children as Americans," he said.

Meanwhile, in Iowa, the first nominating state, Trump is the first choice among 23 percent of likely Republican caucus goers -- jumping from 4 percent in May, according to a Bloomberg/Des Moines Register poll this weekend.

In a surprising surge to second, retired neurosurgeon Ben Carson is polling at 18 percent.

Republican voters appear to be warming to Trump's unconventional and confrontational style.

His favourability numbers among Iowa Republicans have jumped 35 points since January leaving establishment favourite Jeb Bush and others struggling to adapt.