In explaining the abrupt cancellation of Monday's controversial vote to overhaul legislative redistricting, Senate President Stephen Sweeney said more time and input were needed.

"We will maintain an open mind,'' he said in a Saturday night statement.

In the end it wasn't a hunger for more input, but the fierce backlash from the party's liberal base that forced Sweeney and Assembly Speaker Craig Coughlin to beat a humiliating retreat.

The veteran Sweeney and newcomer Coughlin have maintained the upper hand since Gov. Phil Murphy's 2017 election solidified the Democratic Party's "trifecta" dominance in the Statehouse.

Yet their decision to muscle through this controversial and mind-numbingly complicated method of redrawing the boundaries of 40 legislative districts amid the distractions of the holiday season proved to be a colossal misread of the political moment.

Sweeney and Coughlin were caught off guard by the extent of the outcry from good-government groups, academics and, most important, liberal Democratic groups aligned with Murphy.

Misreading grass-roots anger

The Democratic duo had reason to underestimate all the grass-roots liberals.

The two leaders successfully shut down a goal long pursued by the party's liberal activists in June when they opposed major tax hikes on millionaires.

Sweeney and Coughlin, who consider themselves stewards of a more centrist, business-friendly Democratic tradition, also pumped the brakes on a $15-an-hour minimum wage increase, another top priority for the liberal wing. And with a touch of swagger, Sweeney has vowed to seek another round of public employee givebacks on health and pension benefits, which is a direct assault on a core liberal constituency.

But this time Sweeney failed to recognize the angry zeitgeist of the national and New Jersey Democratic Party. Just weeks earlier, the party's grass roots successfully mobilized during the midterms, fueled by fear that Donald Trump and his Republican allies were swiftly eroding long-cherished Democratic institutions.

Activists were also enraged by what they viewed as Republican Party attempts around the country to disenfranchise voters with strict new voter identification laws. And they were enraged by the success of the lame-duck GOP legislatures and governors in Wisconsin and Michigan in stripping power from the incoming Democratic governors and attorneys general.

"What we have nationally is Republicans in many states changing the rules of the game when they don't like the outcome of an election,'' said Patrick Murray, the Monmouth University pollster and leading critic of the proposal.

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For many, it was galling to see majority New Jersey Democrats attempt a similar power grab. It was hypocrisy in action.

"We see a lot of opposition from these progressive groups that suddenly pop up in the Trump era, saying this is exactly the kind of thing they don't like seeing happening. And they don't want to see their fellow Democrats propose it," Murray said.

The furor threatened to turn New Jersey into a national embarrassment within the Democratic Party. The flap drew criticism from the New York Times editorial page, and Eric Holder, former attorney general during the Obama administration, warned that the proposal could undermine national Democrats' attempts to fight Republican gerrymandering efforts around the country.

Liberals, GOP link arms in opposition

The backlash also had the unintended result of creating a strange-bedfellows alliance with Republicans, who feared the measure would turn them into a permanent fringe minority.

“When progressive groups and Republicans come together to oppose a bill, you know it must be a bad concept,” said Assembly Minority Leader Jon Bramnick, R-Union County.

The proposal, which required a constitutional amendment, would have essentially embedded into the constitution a partisan formula for drawing new voting boundaries.

It would require at least 25 percent of the districts to hew closely to the statewide average election results of the previous decade's presidential, gubernatorial and U.S Senate election results.

That would have given Democrats, at least for the next redistricting in 2021, an overwhelming advantage. Republicans can claim only one victory among those contests: former Gov. Chris Christie's re-election in 2013.

But the proposed formula also stirred unease among Democratic lawmakers.

Some feared it could pit incumbents against each other within districts.

“There’s something in this bill to affront almost everybody,” state Senate Majority Leader Loretta Weinberg, D-Bergen, told WNYC radio on Saturday. “That’s not always easy to do. But apparently, that’s what we managed to do.”

There was also concern that strong minority-heavy districts would be diluted in an attempt to comply with the new law.

“It doesn’t take steps to make sure that communities that have been disenfranchised are included in the process," said Jim Johnson, a senior fellow at the Brennan Center for Justice.

Sen. Nicholas Scutari, D-Union, the primary sponsor of the bill, said the proposal would mostly codify the process that was used to redraw maps in 2011. And he noted that the state constitution already provides protections for minority communities.

Was this a win for Murphy?

But now that the proposal has been shelved, Murphy emerged as a relieved victor, scoring a rare political victory amid a year of rookie stumbles.

"I’m grateful [legislators] heard the voices of so many within New Jersey and around the country who saw that the proposal would have made our Legislature less representative and less accountable,'' he said.

It now faces uncertain future.

To get it on the November ballot for voter approval will require require a three-fifths vote of the Legislature, meaning Republican votes will be needed. And the GOP has no intention of supporting the bill in its current form.

Like Sweeney, Coughlin said Saturday that he wants to "integrate some of the valuable input received to help create a better measure."

That would mean bringing the liberal base, good-government advocates and Republicans to the table to hash out an agreement. And no one is counting on that happening in the foreseeable future.