WASHINGTON — Thousands of U.S. troops to stop an “invasion” of migrants. Tent cities for asylum seekers. An end for the Constitution’s guarantee of birthright citizenship.

With his eyes squarely on next Tuesday’s elections, President Donald Trump is rushing out hardline immigration declarations, promises and actions as he tries to mobilize supporters to retain Republican control of Congress. His own campaign in 2016 concentrated on border fears, and that’s his final-week focus in the midterm fight.

Most legal scholars say it would take a new constitutional amendment to alter the current one granting citizenship to anyone born in America.

Trump and many top aides have long seen the immigration issue as the most effective rallying cry for his base of supporters.

With interviews on Fox and “Axios on HBO,” Trump revived some of his hardest-line immigration ideas:

— An executive order to revoke the right to citizenship for babies born to non-U.S. citizens on American soil.

— The prolonged detention of anyone coming across the U.S.-Mexico border, including those seeking asylum, in “tent cities” erected “all over the place.”

“I’ve been saying this long before the election. I’ve been saying this before I ever thought of running for office. We have to have strong borders,” Trump told Fox News host Laura Ingraham in an interview Monday.

Trump’s citizenship proposal would inevitably spark a long-shot legal battle over whether the president can alter the long-accepted understanding that the 14th Amendment grants citizenship to any child born on U.S. soil, regardless of his parents’ immigration status.

Associated Press writers Elliot Spagat in San Diego, Amy Taxin in Santa Ana, California, and Deb Riechmann, Lisa Mascaro, Zeke Miller, Mark Sherman and Eileen Putman in Washington contributed.

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