WASHINGTON -- President Donald Trump responded to demands that unauthorized immigrants brought to the U.S. as children be allowed to remain with a new campaign ad saying Democrats would be "complicit in every murder committed by illegal immigrants."

The 30-second ad was launched after Senate Democrats voted against a Republican spending bill when Trump and GOP lawmakers refused to negotiate a way to protect the so-called dreamers, who face deportation beginning March 5 after Trump revoked their protections.

That led to Saturday's government shutdown.

U.S. Sen. Robert Menendez, a leader of the effort to allow the dreamers to remain in the country they grew up in, immediately criticized the ad.

"Donald Trump responded as he always does when his failures of leadership shine a negative light on him: with more racism, more xenophobia, and more white nationalism," said Menendez, D-N.J. "I wish I could say that I'm shocked that he would try to politicize the grief that these families have experienced, but I'm not."

"Instead of deflecting and dividing, and calling for a good shutdown, maybe he needs to understand that we need a good solution," Menendez said.

The Trump campaign defended the ad.

"Donald Trump was elected president to build the wall and keep American families safe from evil, illegal immigrants who commit violent crimes against lawful U.S. citizens," said Michael S. Glassner, executive director of Trump's campaign committee.

"Our new campaign ad draws attention to the stark contrast between 'complicit' Democrats and the president for his full commitment to build a wall and fix our border to protect Americans from drugs, murder and other atrocities," Glassner said.

The immigrants in question, including 17,400 in New Jersey, are known as "dreamers" after the Development, Relief, and Education for Alien Minors Act that would have allowed them to remain in the country legally if they attended college or joined the military. Senate Republicans blocked that legislation.

Because the Democrats support the dreamers, the ad accuses them of also defending unauthorized immigrants who are "pure evil," such as one accused of killing two police officers who wished he had "killed more."

This is despite the fact that Trump also called for allowing the dreamers to remain in the U.S. even after he revoked President Barack Obama's Deferred Action for Childhood Arrivals program in September.

Congress now has 6 months to legalize DACA (something the Obama Administration was unable to do). If they can't, I will revisit this issue!
-- Donald J. Trump (@realDonaldTrump) September 6, 2017

Menendez is part of a bipartisan group of six U.S. senators who agreed to strengthen border security and fund the wall that Trump said Mexico would pay for in exchange for allowing the dreamers to remain in the U.S. legally.

When members of that group visited Trump at the White House to present the bipartisan compromise, the president responded by calling Haiti and African nations "shithole countries" and rejected the deal.

The Trump campaign launched the ad in the wake of recent polls indicating that Americans would blame the Republicans who control the White House and Congress for the shutdown, not the out-of-power Democrats.

In a Quinnipiac University poll, 53 percent said they would blame either Trump or congressional Republicans, while 34 percent said congressional Democrats were responsible. A CNN poll said 47 percent of Americans would pin the blame on Trump or congressional Republicans and 31 percent on Democrats.

And an ABC News/Washington Post poll said almost half of Americans, 48 percent, would blame Trump and the Republicans, while 28 percent said they would blame the Democrats.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.