Nothing brings the United States Senate together quite like larding up a farm bill with goodies for their constituents. But the goodwill and cheer is about to end, as the Senate today voted 84–15 on Tuesday to proceed with debate on so-called comprehensive immigration reform. The measure is splitting coalitions in unpredictable ways, pitting natural allies against one another and deepening generational intraparty rifts.

Immigration reform has eluded policymakers for at decades now. The last major legislation was the Immigration Reform and Control Act of 1986, in which about 3 million unlawfully present immigrants were granted legal status with promises of future border security. While advances have certainly been made in controlling our southern border, those promises have mostly been broken.

The current bill was designed by the bipartisan Gang of Eight in the Senate. The idea is that if four prominent senators from each party can craft a piece of legislation they are all willing to sponsor, the bill should be able to pass the rest of the chamber.

The Gang of Eight bill works like this. Anyone who was here before a certain date—December 31, 2011—are eligible for “Registered Provisional Immigrant” status. No felons, no terrorists, and there is an application process. Those granted RPI status are then eligible for an expedited adjustment to legal permanent resident. There’s an application process with a lot of conditions—including paying any taxes that have been “assessed” and paying a fee that reaches the four-digit mark. Critics object that the IRS has not assessed taxes on many of these immigrants and that the fee, spread over a number of years, is really no impediment to status.

The real objection is that there is no real commitment to securing the border. The Senate Report that accompanies the Gang of Eight bill acknowledges the failures of previous immigration reforms, including failure to address the causes of massive illegal entry. Although Mexican immigration is approximating a net zero at this point, a porous thousand-mile border with an impoverished nation presents obvious threats.

While border state residents and the security-conscious bristle at the weak-tea border control measures in the bill, the millions of Mexicans already here present a sticking point on the other side. Everyone (well, everyone in Washington) acknowledges that 11–20 million people are not going to be rounded up and deported. And most are now saying that isn’t even desirable. If the conservative talking point is the safety of the U.S. people and terrorism-related concerns, the liberal line is “bringing people out of the shadows.”

I tend to sympathize more easily with the security and sovereignty concerns, while our own Helen Lee emphasizes the relational element of immigration policy. Both “sides” of this difficult issue speak to the essence of who we are as a nation. As I write this, Senate Judiciary Committee chairman Patrick Leahy is posturing on the Senate floor about refusing “costly or inhumane” border security measures. Soon a Republican will rise to posture about allowing lawbreakers to jump in front of law-abiders in the immigration queue.

There has been a lot of good faith discussion and bill writing over the past few months, with only a minimum of partisan absurdity. Soon that will be a distant memory.

Now, before the toxic volcano of partisanship erupts this week, is the time to reflect on the right way forward. A nation that cannot control its borders is not long a nation; a nation that perpetuates a laboring underclass that can’t vote probably shouldn’t long be a nation. Let’s pray that our leaders can thread this needle wisely, coherently, and humanely.