The Senate is expected to vote Tuesday on whether to begin debate over an immigration bill.
The vote was to start a road down the path to comprehensive immigration reform—the first major reform in nearly 30 years. While it wasn't supposed to be easy, the anticipation was that finally, the immigration issue would be settled.
That's no longer the case, said one analyst.
"Passage of a bill is becoming much more doubtful," said Bill Helfand, a civil rights and employment lawyer at Chamberlain Hrdicka.
"What started out as a consensus on reform has crumbled into partisan bickering," Helfand explained. "We were impressed that the two political parties were working together on this, and that Washington would get something done. But that's no longer the case."
A recent stumbling block is the issue of border security. Republicans in the House and Senate have called for stricter border controls than what's currently in the bill put together by the so-called "gang of eight" bipartisan senators.
The bill itself calls for spending an additional $6.5 billion a year on border security as well as increased training for any U.S. agents within 100 miles of "any land or marine border of the United States." The bill also calls for more Border Patrol stations within the 100-mile band, for improved communications there, and for the use of surveillance drones.
(Read more: Immigration Bill 'Could Create DMZ' Like Korea)
The U.S. currently spends some $18.5 billion each year on U.S. border security.
But Senator John Cornyn (R-Texas) —who is not one of the eight —has proposed an amendment that calls for more expensive, stringent border security triggers that must be met before a pathway to legalization for some 11 million undocumented workers can be considered in the Senate immigration reform bill.
Cronyn's proposal has had support from Senator Marco Rubio (R-Fla.), who is one of the gang of eight.
"The bottom line is, there is a vibrant debate going on in the Republican Party," Rubio told reporters after a meeting with House Republicans last week on the immigration measure. "I can tell you that the bill as currently structured isn't going to pass in the House, and I think it's going to struggle to pass in the Senate."
"The current GOP lobbying for greater enforcement measures is not new to legalization discussions," said Evie Jeang, an immigration lawyer and managing partner with Ideal Legal Group.
(Read more: How Immigration Reform Could Boost Real Estate
"A lot of this can be explained as negotiations and playing politics," Jeang explains. "Much of the GOP supports reform to broaden their political base with immigrants, but at the same time this posturing is to appease conservatives."
For their part, congressional Democrats and some pro-immigration reform groups have called Cornyn's proposals a roadblock on the path to citizenship for millions of illegal immigrants.
Another sticking point is health care. The current proposal states that immigrants who embark on the "path to citizenship" will not qualify for affordable health insurance under the Obama administration's health care law during the 10 to 15 years it will take to complete the citizenship process
But Rep. Raúl Labrador (R-Idaho) said last week he was leaving a House group working on immigration reform because of concerns that the bill would not sufficiently protect taxpayers from footing the health care bill of immigrants in the country illegally.
"Labrador's exit is a prelude to the volatility in the House on immigration reform," said Jaime Longazel, a professor of sociology and an immigration expert at the University of Dayton.
"The House is likely to insert many more hurdles in the path to citizenship if they keep citizenship in the bill at all," Longazel said.
Perhaps no senator more than Republican Jeff Sessions of Alabama has been more vocal about his opposition to the current bill. Sessions is considered a driving force behind the efforts to kill an immigration reform in 2008.
Sessions has been an outspoken advocate for a 700-mile double fence along the 2,000-mile U.S. Mexico border and introduced some 49 amendments to the current bill, among them calling for English to be the official language of the U.S.
"We create amendments that reveal the problems with [the immigration reform bill], and I think that's kind of what's been happening," Sessions has said. "We are beginning to show that there are weaknesses in it."
It's not just politicians who don't like the bill as it stand. Opposition comes from the two unions representing the immigration and customs officers..
The leaders of unions representing workers at the federal Immigration and Customs Enforcement and the U.S. Citizenship and Immigration Services said in a letter sent to lawmakers last month that the Senate measure is too weak on securing the borders in part because it doesn't provide for enough agents.
As for the bickering over immigration reform, it says more about the American political system than immigration itself, said Longazel.
"Compromise is gone and replaced with the usual political calculating," Longazel said. "Concerns about the social impact of a bill are undermined by concerns about re-election."
"Then there will be a staring match between the Senate and House as to whether that legislation is brought together with comprehensive Senate legislation into conference," said Mark Noferi, a law professor and immigration analyst at the Brooklyn School of Law
"The House leadership would like to take less extreme positions, so as not to alienate large portions of the country, but the rank and file may have little political incentive to do that," Noferi added.
On Tuesday, President Obama urged Congress to pass the bill saying that it is a compromise that doesn't satisfy any group's needs entirely but represents the "best chance" to repair a broken system."
"The immigration debate is alive and well, and while it's a polarizing issue, there's more common ground between the two sides than ever before," she Evie Jeang. "Those in Congress don't want to alienate immigrant groups who make up a large percentage of the voting public."
(Read more: Top Republican Sees U.S. Immigration Bill by Year's End)
Others remain skeptical anything will get done.
"It's very disappointing what's happening with reform," said Bill Helfand. "The complete lack of progress suggests the whole country as a whole loses if this isn't done. I can't say I'm as optimistic as I once was. It's just disappointing."
This story is by CNBC' Senior Editor, Mark Koba