WASHINGTON (AP) — Democrats ignored a White House veto threat on Tuesday and muscled legislation toward House passage that would give a chance for citizenship to an estimated 2 million-plus migrants — a bill that stands virtually no chance of becoming law but lets them showcase their efforts on one of their highest-profile priorities.

The measure is only one skirmish in Democrats' multi-front battle against President Donald Trump and most congressional Republicans over immigration, an issue that has deadlocked the two parties for decades. It is likely fated to join a host of other House-passed measures advancing Democrats' agenda that are running aground in the GOP-run Senate, including legislation on health care, gun control, climate change and election security.

As if to underscore the relentlessness of the immigration fight, the Democratic-led House Appropriations Committee took its own swipe at Trump by unveiling a separate bill that provides no additional money next year for building the president's long-sought barriers along the southwest border. The House bill also claws back a portion of the billions of dollars Trump has unilaterally diverted toward constructing portions of his wall.

The measure the full House debated would protect from deportation — and provide a pathway toward citizenship — for young migrants brought to the U.S. illegally as children, in addition to others here temporarily because their home countries — chiefly in Central America, Africa and the Middle East — have been ravaged by wars or natural disasters.

Many of the beneficiaries would be "Dreamers" currently protected by the Obama-era Deferred Action for Childhood Arrivals program, or DACA, which only the federal courts have prevented Trump from dismantling.

The nonpartisan Congressional Budget Office estimated that more than 2 million people already in the U.S. would get legal status under the House bill. The analysts also said the House bill would cost more than $30 billion over the next decade, largely because many of the migrants attaining legal status would qualify for Medicaid and other federal benefits.

Republicans say the bill lacks border security provisions that they and Trump have long demanded as part of any major immigration bill. White House aides sent lawmakers a letter threatening a Trump veto, saying the measure "would incentivize and reward illegal immigration" without "protecting our communities and defending our borders."

Democrats said that besides humanitarian considerations, helping the migrants stay in the U.S. would benefit the economy and the many industries that employ them as workers. They noted that among the bill's supporters is the U.S. Chamber of Commerce.

"This is about who we are as Americans, and what is in the best interests of our country," said Rep. Lucille Roybal-Allard, D-Calif., the measure's chief sponsor.