The battle over immigration has been intensified by heartbreaking images of migrant children separated from families and complicated by opaque statements by President Donald Trump.

WASHINGTON — The House Republican immigration overhaul dangled precariously Thursday, imperiled by stubborn differences between conservative and moderate factions — and by President Donald Trump’s running commentary about a bill he only half-heartedly supported and then suggested would never become law.

Republican leaders were twice forced to postpone final voting, first until Friday and then punting it to next week, as negotiators made a last-ditch push for support. They were trying to persuade colleagues to seize the moment and tackle immigration problems by approving the bill, which includes $25 billion for Trump’s border wall and a path to citizenship for young immigrants who have lived in the U.S. illegally since childhood.

House Majority Whip Steve Scalise of Louisiana said Thursday evening they would keep trying to find consensus on the legislation.

Earlier in the day, Speaker Paul Ryan had appeared resigned to defeat, instead holding out hope that the compromise negotiated among the Republican House majority could sow the seeds for an eventual resolution.

“I actually think we’re advancing the cause even if something doesn’t necessarily pass,” he said. “I think we’re making advancements.”

And they weren’t ready to give up.

GOP lawmakers leaving a two-hour closed-door meeting said there were plans to add two provisions to the sweeping legislation to attract more backing.

One would require employers to use an online system to verify the citizenship of their workers, which could attract conservatives. The other would make it easier for employers to retain migrant workers, which could bolster support from Republicans from agricultural regions. Legislation on those issues had been promised for July, but skeptical lawmakers wanted it done sooner.

The turmoil among Republicans over the bill, hardened in recent days by heart-wrenching images from the crisis at the border — with families separated and young immigrants kept in fenced holding areas — showcased the limits of a go-it-alone GOP immigration strategy.

Republicans have never been able to pass a big immigration overhaul on their own, despite talking about the issue for years. The potential collapse of their latest effort underscores the reality that it probably will require bipartisan consensus to find immigration solutions, even as Republicans control both Congress and the White House.

Trump acknowledged as much. “We need two to tango,” he said at the White House.

His offhand comments, coming before votes were cast Thursday, hardly helped an already tenuous situation. Maybe he should invite Democratic leaders Nancy Pelosi and Chuck Schumer to the White House, he suggested.

“We should be able to do a bill. I’d invite them to come to the White House any time they want. This afternoon would be good,” Trump said. The Democratic leaders did not arrive.

In fact, the Democrats showed no interest in helping the Republicans without fundamental changes to include their own priorities.

“It is not a compromise,” said House Minority Leader Pelosi. “It may be a compromise with the devil, but it is not a compromise with the Democrats.”

Rather than help push the bill to the finish line, Trump’s mixed messages reinforced his role as an unreliable partner for House Republicans in the immigration debate. First, he had distanced himself from the negotiations. Then, he interjected that he didn’t like what they came up with. Then he reversed course and said he would back the compromise — as well as a more conservative measure that went down to defeat earlier Thursday.

But then he tweeted on Thursday that whatever passed in the House was surely dead in the Senate because Republicans have just 51 votes, not nearly enough to clear the 60-vote threshold to get past a Democratic filibuster.

“What is the purpose of the House doing good immigration bills when you need 9 votes by Democrats in the Senate, and the Dems are only looking to Obstruct (which they feel is good for them in the Mid-Terms),” Trump tweeted.

That comment came just two days after the president swooped into the Capitol to endorse the bills.

Fence-sitting Republicans or those otherwise opposed to the legislation said they felt little pressure to come on board the compromise bill or a measure favored by conservatives that was defeated on Thursday.

“I’m not spending my political capital or my brain cells on these two bills,” said conservative Rep. Thomas Massie of Kentucky, opposes both.

The House voted 231-193 to defeat the more conservative version that would have authorized border wall funds but not a path to citizenship for the young immigrants. All Democrats and 41 Republicans opposed the legislation.

Meanwhile, the compromise measure remained in limbo. Rep. Randy Weber, R-Texas, a member of the conservative Freedom Caucus, said, “I’m thinking we’re banging our head against the wall and it’s not even built yet.”

Other Republicans, though, particularly moderates who forced the immigration issue to the fore, pushed on, trying to persuade their colleagues not to let this chance slip away. Many come from states with large immigrant populations now at risk of deportation after Trump ended the Deferred Action for Childhood Arrivals program. The program is temporarily still in effect, pending further federal court action.

“This is the most consensus bill you can get on a contentious issue,” said Rep. Peter King, R-N.Y. He said if Republicans can’t get it done, “you end up looking like the gang that can’t shoot straight.”

But a small group of influential moderates was also feeling burned after long negotiations with conservatives in the House Freedom Caucus and the Republican Study Committee, which make up the bulk of the GOP majority and appeared poised to abandon the compromise.

Rep. Carlos Curbelo, a leading GOP moderate from Florida, shouted on the House floor about the inability of his colleagues to accept the deal.

“That’s the problem with immigration, nothing’s ever good enough.”

Rep. Jeff Denham of California, a champion of the compromise, complained as he left a meeting with all the groups in the speaker’s office: “The goal posts have continued to move throughout the entire negotiations.”

He said, “There’s only one way that this bill goes down today and that’s if the Freedom Caucus votes against the measures that they put into the bill.”

But Rep. Mark Walker of North Carolina, head of the Republican Study Committee, called the compromise “toxic” and urged a one-week delay in voting.