The path for immigration reform has not only been a twisted one; it has had more stop and go lights than Fifth Avenue from lower Manhattan to Harlem. Before you finish reading the next paragraph the light is likely to change, so making any predictions about the outlook for comprehensive—or not so comprehensive—reform is rolling the dice at best.

Immigration policy and the laws that implement it have been one of the most contentious subjects of debate for at least a century: restrictive limits on immigration based on race and ethnic origin in the 1920s; the bracero program of the 1940s and ’50s, which was designed to assure an adequate labor supply for agriculture; the surge of Vietnam refugees in the 1970s; two different but failed attempts to resolve the flow of illegal immigrants in the 1980s and ’90s; through today’s ongoing controversy over sealing the border or providing legal status to those who came here illegally. These debates have always engendered strong emotional reactions on all sides.

The current debate centers on the four pillars of reform acknowledged by most participants as issues that must be addressed. First, is the question of securing our borders. How do we physically secure the border? What are the benchmarks that must be achieved in order to trigger other parts of the reform process? How do we design a system to know if people who enter the country legally are leaving at the end of their permitted visa stay?

Second, there is the issue of work visas. How many workers should be permitted to enter the country each year? Should it rise or fall with economic conditions or should the number be fixed? Should there be separate categories for high skilled and low skilled worker visas?

Third is the difficult task of constructing a system that will ensure that every person who takes a job is either a citizen, permanent resident, or has one of the work required work visas. Non-discriminatory implementation of the system is probably even more difficult than its design.

Finally, there is the elephant in the room: What do we do about the roughly ten million persons who are in the country today in a non-legal status—people who either entered illegally or came with a legal visa but then simply stayed beyond the expiration of that visa. Should they be given legal status? Can that legal status be converted into citizenship, or do they remain in permanent limbo—legally in the United States, but never eligible for citizenship?

For each of these questions, there are scores, if not hundreds, of other sub-questions we must resolve. It is hard to find in the annals of legislative proposals of the past fifty years an issue as complex or daunting as immigration. Overlaying the technical challenges of drafting legislation are emotions that run the gamut from those who believe it is a simple matter of fairness to those who insist it is a matter of the rule of law and who believe that persons who are here illegally should not be rewarded with legal status of any sort.

There is still another layer on top of all this: the politics of immigration. Both proponents and opponents of reform acknowledge the fact that the United States is rapidly becoming a country where the majority of persons residing here will claim minority status: Native Americans, Hispanics, African-Americans, Asians. But the fastest growing of these groups is the Hispanic population, and that poses special problems for Republicans, who rightly fear losing any political traction with this population if they oppose immigration for its members.

Over the past several years we have witnessed open conflict between these two factions within the Republican Party. The Republican-dominated House introduces omprehensive reform legislation in 2005, but it came at a time when anxiety about the flood of illegal immigrants was at its peak. The legislation was never considered. Two years later, the Senate came within one vote of getting the necessary number to pass a similar comprehensive piece of legislation introduced by Senators McCain and Kennedy. With the passing of another election, Democrats were in control of the House, Senate, and White House, but still could not pass a comprehensive reform bill.

Since taking back the House in 2010, Republicans have grappled with the issue, while the Senate managed to pass an imperfect but nonetheless comprehensive approach to the issue in 2013. Only weeks ago, the Speaker of the House signaled that this was going to be a legislative priority for the House in 2014 by hiring a well-known expert on immigration policy to shepherd the issue through the House. Then, at their “retreat” in late January, House Republicans adopted a set of principles (they insist on referring to them as “standards”) that seemed to put them squarely on the path to adopting not one but a number of individual bills that would incorporate all the key elements of reform. Less than a week later, however, the Speaker seemed to dash the hopes of reform advocates by saying at his daily news conference that immigration reform would likely not be brought up in 2014.

So, what is going on? Was this a tactical move to get more leverage with the White House or with the Senate? Did the Speaker hear from the rank and file strong objections to the standards their own caucus adopted a few days earlier? Or did the leadership decide it was unwise to introduce such a controversial issue into the political mix when hammering away on Obamacare seemed to be the winning issue heading into this fall’s midterm elections.

Most likely, it was a combination of all these factors that led to the decision to lay immigration aside for the current session of Congress. At least, that is what it looks like this week on Capitol Hill. But the issue isn’t going to go away. One thing is certain. Until the immigration question is dealt with, millions of immigrants and Americans—workers and employers—will be stuck in the crosswalk, wondering if the traffic light is red or green.