President Joe Biden’s proposal for wide-ranging immigration reform — which he sent to Congress on the first day of his presidency — was unveiled by Democrats on Capitol Hill Thursday.

The plan includes a path to citizenship for approximately 11 million undocumented immigrants currently living in the U.S., a measure that would prevent travel bans based on religion, a plan to reduce immigration backlogs and an aim to address the root causes of Central American migration, among several other proposals.

It’s the first major push for reform since a bipartisan 2013 measure that failed in Congress. But President Biden’s plan goes even further, leaving critics to balk at the sweeping measures and advocates to cheer its promise of change.

A senior administration official deemed it a chance "reset and restart conversations on immigration reform after the last four years."

The bill — titled the U.S. Citizenship Act — is being introduced by Rep. Linda Sanchez (D-CA) on the House side Thursday and Sen. Bob Menendez (D-NJ) in the Senate next week.

"Our current system is riddled with inefficiencies and needless cruelties," Sen. Menendez told reporters Thursday. 

"We have 11 million undocumented people living, working and raising families in our communities without legal steps. These are good and decent people who believe in the promise of America down to their bones," he added.

Menendez was one of the bipartisan "Gang of 8" senators that attempted to negotiate the 2013 bill, which ultimately fell apart. A bill backed by George W. Bush also failed in Congress prior to that.

Experts are quick to acknowledge that the bill has almost no chance to pass in its current form, since the sweeping measures won't garner enough support from Senate Republicans or even some moderate Democrats. 

President Biden himself said he’s willing to see his immigration priorities separated into their own legislation, including in a CNN town hall Tuesday night, though he did say a path to citizenship was an essential element.

“There's things that I would deal [with] by itself, but not at the expense of saying, ‘I'm never going to do the other,’” Biden told CNN’s Anderson Cooper. “There is a reasonable path to citizenship.”

On Thursday, Sen. Menendez addressed the lack of GOP support for the bill.

"I have had conversations with various Republican colleagues. Many of them have interest in parts of the legislation," he said, noting his openness to negotiation. "But what we are looking for is robust reform."

A likely scenario is that Congress would first move to create a pathway to legalization for two groups: farmworkers and others who have had nonpermanent status, such as those covered by Deferred Action for Childhood Arrivals and Temporary Protected Status. The House already passed similar legislation addressing both groups during the last Congress.

In the meantime, advocates say that the comprehensiveness of Biden’s bill is at least an important sign of the president’s desire to make reforms that never came to fruition during the Obama administration. 

“This is the broadest legalization proposal by a president that we've seen,” Jessica Bolter, an Associate Policy Analyst at the Migration Policy Institute, told Spectrum News. “Just for that reason — solely as a kind of symbolic and messaging reason — this is a really significant proposal.”

Getting Republican support for a bill packed with so many major changes is unlikely in the Senate, especially since senators can use the filibuster to prevent the measure from getting a vote.

While the 2013 reform bill was drafted with input from GOP senators like Lindsey Graham (R-SC) and Marco Rubio (R-FL), neither is expected to get on board with the 2021 version as it’s written. The plan is a “non-starter,” Sen. Rubio said in a statement last month.

On Thursday, the Democratic lawmakers spearheading the legislation said they're open to various methods to get the majority of the bill passed.

"All options are on the table," said Rep. Linda Sanchez (D-CA). "There are other great immigration bills that we also will be taking up and hopefully passing as well."

That’s why the U.S. Citizenship Act is likely to get broken up, and there are a few elements that already have both sides’ support. One example is DREAMers, undocumented immigrants who came to the U.S. as children.

Already, the DREAM Act was reintroduced by Senators Dick Durbin (D-IL) and Lindsey Graham (R-SC) early this month, which would renew the DACA program and provide a path to permanent residence and eventually citizenship. Addressing DACA could be the most urgent part of Biden’s immigration proposal, since it’s being challenged in a Texas court right now.

Besides legalization, another sticking point for Republicans is the lack of border security measures in the U.S. Citizenship Act. It calls for more technology at ports of entry and more training for border officers but no major enforcement changes. 

A senior administration official described Biden's plan for the border as "what works," acknowledging that it might not be bipartisan. 

"This is a common sense approach to addressing the border," the official said. "What's clear that does not work is just having a wall and not addressing the reasons why people are coming."

Bolter said the lack of focus on border security is a lesson learned from the Obama administration.

“There was never enough enforcement for many Republicans,” Bolter said. “And I think that's the lesson that the administration has learned—that even if you do increase enforcement spending, that's not necessarily going to get you the bipartisan support you're looking for.”

As far as timing, advocates say that they don’t expect anything major to pass in the next month, especially with the economic relief bill — the American Rescue Plan — as the administration’s top priority. They do hope for some movement in the next few months, however, since the White House is coordinating with Democrats on Capitol Hill.

The core of the bill is largely unchanged from the measures laid out by the White House on Inauguration Day.

President Biden's plan for the legalization of undocumented immigrants would allow them to apply for temporary status and then for a green card after five years, as long as they pass background checks and have paid their taxes. Green card holders can then go through the process to become a U.S. citizen three years later.

The majority of undocumented immigrants have been in the U.S. for more than a decade, according to a report from the Migration Policy Institute. 

Biden’s proposal also includes the NO BAN Act, which would prevent future immigration bans based on religion, like the one President Donald Trump implemented in his first year that blocked travel from Muslim-majority countries. The measure passed the House last year but never got a vote in the Senate.

The bill also seeks to boost employment-based immigration by eliminating caps on the maximum number of visas allotted to each country and making the application process more efficient. 

At the border, it plans for new scanning technology and other improvements at ports of entry, plus more training and resources for border patrol officers, including those who work in detention centers.

The U.S. Citizenship Act also has measures to address the root causes of Central American migration, the main driver of thousands of people toward the U.S.-Mexico border in recent years. That includes a four-year, $4 billion plan to look into the origins and aid Guatemala, El Salvador and Honduras while also setting up processing centers throughout Central America to “register and process displaced persons.”

Read more about all of the measures expected in the bill here.