Blaming President Barack Obama for messing up the immigration system in the US, Republican presidential candidates talked tough on illegal immigration, describing it as a "serious problem" with Louisiana Governor Bobby Jindal calling it "an invasion".

Business tycoon Donald Trump took credit for brining the issue of illegal immigration to the attention of the Americans and said a wall needs to be built to keep "illegals out".

"So, if it weren't for me, you wouldn't even be talking about illegal immigration. This was not a subject that was on anybody's mind until I brought it up at my announcement," Trump said in the Prime Time Republican primary debate hosted by Fox News in Cleveland, Ohio yesterday.

Trump, who has drawn flak for his remarks in the past that Mexico is sending people bringing drugs, criminals and rapists into the US, said, "killings, murders, crime, drugs (are) pouring across the border, money (is) going out and the drugs coming in.

He said a wall has to be built quickly, even with "a big beautiful door" that allows people to come into the US legally.

"But we need to build a wall, we need to keep illegals out," he said.
Former Florida Governor Jeb Bush, who has been trailing in second place behind Trump in the polls, said America needs to control its border and it is the responsibility of the US to pick and choose who comes in as he opposed extending amnesty to illegal immigrants.

"We need to be much more strategic on how we deal with border enforcement, border security. We need to eliminate the sanctuary cities in this country. It is ridiculous and tragic that people are dying because of the fact that -- that local governments are not following the federal law. There's much to do," he said.

Accusing Obama of talking about immigration as a "wedge issue" for the last six years, Bush said as the next President, he "will fix this once and for all so that we can turn this into a driver for high sustained economic growth."

Earlier, seven of the 17 Republican presidential candidates appeared at Fox News's second-tier debate.

Indian-American Jindal, who could not make the cut for the prime time debate, described immigration without simulation as "an invasion".

"Immigration without simulation is an invasion. We need to tell folks who want to come here they need to come here legally. They need to learn English, adopt values, roll up their sleeves and get to work," he said.

Jindal reiterated his position on "hyphenated Americans and the divisions," saying he was tired of "hyphenated identities." He has in the past insisted that Americans are not "Indian-Americans or African-Americans or Asian-Americans" but just "Americans."

During the prime-time debate, Trump, on being asked if he has specific evidence that the Mexican government is sending criminals across the border, said Border Patrol personnel "say this is what's happening".

He termed American leaders "stupid" for allowing criminals to sneak in through borders.  
"Because our leaders are stupid. Our politicians are stupid. And the Mexican government is much smarter, much sharper, much more cunning. And they send the bad ones over because they don't want to pay for them. They don't want to take care of them. Why should they when the stupid leaders of the United States will do it for them? And that's what is happening whether you like it or not," Trump said.

Wisconsin Governor Scott Walker said Obama, particularly through last November, has messed up the immigration system in the country.

Strongly calling for a secure border, Walker said international criminal organisations are penetrating America's southern based borders. "Secure the border, enforce the law, no amnesty, and go forward with the legal immigration system that gives priority to American working families and wages," he said.

Ohio Governor John Kasich appeared to agree with Trump and said he is touching a nerve because people want the wall to be built.

"They want to see an end to illegal immigration. They want to see it, and we all do. But we all have different ways of getting there," he added.

Florida Senator Marco Rubio said majority of people coming across the border are not from Mexico but are coming from Guatemala, El Salvador, Honduras.

He said the problem of illegal immigration will not go away by simply building fence because tunnels can be build underground hat will facilitate illegal entry.

"And that's why you need an e-verify system and you need an entry-exit tracking system and all sorts of other things to prevent illegal immigration. But I agree with what Governor Kasich just said. People are frustrated. This is the most generous country in the world when it comes to immigration.

There are a million people a year who legally immigrate to the US, and people feel like we're being taken advantage of. We feel like despite our generosity, we're being taken advantage of," he said.

He said given the broken immigration system, many people who have been waiting for years to enter the US legally are now "wondering, maybe they should come illegally."

"It's a serious problem that needs to be addressed, and otherwise we're going to keep talking about this for the next 30 years, like we have for the last 30 years," Rubio said.

Texas Senator Ted Cruz blamed America's leaders for not wanting to enforce immigration laws.

"President Obama has talked about fundamentally transforming this country. There's 7 billion people across the face of the globe, many of whom want to come to this country. If they come legally, great. But if they come illegally and they get amnesty, that is how we fundamentally change this country, and it really is striking. A majority of the candidates on this stage have supported amnesty. I have never supported amnesty," he said.