No amnesty. We’ve seen this movie before.

President Trump gave supporters of immigration enforcement a jolt Sunday night. In an interview with CBS News’ “60 Minutes,” he called his administration’s deportation policy “too tough” and entertained a deal with Democrats that could allow some people here illegally to stay. The president who promised mass deportations has put legal status back on the table.

Trump spoke sympathetically of hotel and landscaping workers who have lived here for 10 or 15 years. He offered no plan or eligibility rules. On Monday, Homeland Security Secretary Markwayne Mullin said amnesty was out of the question. Good. But after the president’s remarks, a warning is in order: We have seen this “bargain” before. It failed.

Migrants are plainly paying attention to Washington’s political signals. Congress should pay attention to