The debate over birthright citizenship has been given a key role in the 2016 US presidential contest by Republican hopeful Donald Trump, who raised the issue in his radical immigration plan.
The draconian immigration proposal that Trump presented on Sunday - calls for the deportation of the country's estimated 11 million undocumented migrants - was seconded Monday by one of his rivals for the Republican nomination, Wisconsin Governor Scott Walker.
Besides the unprecedented mass deportation, the billionaire real estate developer advocates ending automatic citizenship for the US-born children of undocumented immigrants.
Ending birthright citizenship would require the repeal or drastic revision of the fourteenth amendment to the Constitution, enacted following the US Civil War.
"Well it's similar to what I brought up about four or five months ago. In fact, earlier in the year I was on Fox News Sunday and laid out what I thought we should do," Walker said on Monday in an interview on the conservative TV channel.
The belligerent speech on immigration, with which Trump took over the campaign from the time he announced his candidacy on June 16, has forced his 16 rivals in the Republican primaries to toughen their stance on a very sensitive subject for Latinos.
Latinos are a decisive electorate in the presidential balloting that traditionally favors the Democratic Party.
Walker, who in 2013 said that looking for a path to citizenship for the undocumented "made sense", admitted that he has changed his mind and now favours his party's opinion that such a measure amounts to "amnesty".
Trump's plan also forced New Jersey Governor Chris Christie to speak up on Monday, since he needs some traction in the polls.
The combative governor strongly attacked Donald Trump's big plan to construct a wall on the border to halt illegal immigration and have Mexico pay to build it.
"This is not negotiation of a real estate deal, O.K.?" Christie said on CNN in reference to Trump's lack of political experience.
Nonetheless, Christie is open to accepting one of the most controversial ideas that Trump has made a campaign issue - eliminating the right to birthright citizenship as guaranteed by the US Constitution.
"I think all this stuff needs to be re-examined in light of the current circumstances. (Birthright citizenship) may have made sense at some point in our history, but right now, we need to re-look at all that," he said during an August 12 interview on Laura Ingraham's conservative talk show.
That same day another Republican hopeful, Ohio Governor John Kasich, admitted he has changed his mind - he no longer says the US must give automatic citizenship to people who are born in this country, as he had previously argued as a member of Congress.
At that time he expressed his now-altered position in an interview on CNN where he said: "Let these people who are born here be citizens and that's the end of it. I don't want to dwell on it."