Central American asylum seekers wait as U.S. Border Patrol agents take groups of them into custody on June 12, 2018 near McAllen, Texas.

American voters broadly oppose the Trump administration policy of separating immigrant families at U.S. borders, according to a poll released Monday.

The survey underscores the political backlash the White House and closely associated congressional Republicans face if President Donald Trump does not abandon the practice.

Sixty-six percent of voters oppose the policy of splitting up parents and children who cross the border illegally, versus only 27 percent who back it, according to a Quinnipiac University poll. The findings vary greatly by party leaning.

More than half of GOP voters — 55 percent — support the policy, while 35 percent of Republicans are against it. Among Democrats, 91 percent of voters oppose separating families and a mere 7 percent back the practice.

Importantly, independents — who will help to determine winners in swing races in November's midterm elections — are largely against the policy. Sixty-eight percent of independents oppose it, while 24 percent back it.

Activists, religious groups and bipartisan lawmakers have condemned the practice as inhumane. Some lawmakers have urged Trump to swiftly end the policy.

The president has blamed family separation on Democrats and claimed that only congressional action will resolve the crisis. However, his administration made a deliberate choice to boost criminal prosecution of people who cross U.S. borders illegally, therefore leading to the separation of families.

The Quinnipiac poll taken from June 14 to June 17 surveyed 905 voters nationwide and has a margin of error of plus-or-minus 3.9 percentage points.