This vote was the third of three attempts to close debate on a large immigration overhaul (the previous two attempts were unsuccessful).

This vote occurred on an attempt to bring debate on a bill to a close (known as a "cloture motion" in the Senate). If the Senate votes to "invoke cloture" – or bring debate to a close – then lawmakers must either hold a vote on the legislation or amendment in question, or move on to other business. This type of motion is most often called on contentious bills or amendments where the leadership is concerned that consideration could be held up indefinitely by a handful of unhappy politicians.

The motion was called on a bill that represented a bipartisan compromise reached between Democrats and Republicans on changing immigration policies. It was the third such attempt by Democrats to limit debate on the bill (the prior two motions failed).

The bill represents a hard-won compromise between competing sides of the immigration debate: those who want to give the nearly 12 million illegal immigrants a chance to legitimize their residency either temporarily or permanently, and those who want to tighten security along America's border with Mexico. To that end, the bill would establish several new visas that allow immigrants to work temporarily or put them onto a path to citizenship. But for these visas to be activated, the government must first certify that several other initiatives intended to strengthen America's border included in the underlying bill have been implemented.

After nearly two weeks of plowing through amendments, most of them offered unsuccessfully by Republicans, Senate Majority Leader Harry Reid, D-Nev., called a cloture vote to bring debate on the measure to a close and move the Senate toward a final vote on the bill. This vote was on the third such cloture motion Reid offered; the first two were unsuccessful. After the second motion failed, Reid spend several hours behind the scenes trying to negotiate with Democrats, then called one more cloture motion.

Republicans complained bitterly that Democrats had not allowed them enough time to offer all the amendments they wanted, while Democrats answered that they had days in which to offer amendments and that it was time to wrap things up. Senate Majority Leader Harry Reid, D-Nev., answered that Republicans are doing little more than engaging in delaying tactics, and that even after cloture is invoked Republicans will have an extra 30 hours in which to offer and debate amendments.

By a vote of 45-50, the Senate rejected the motion to invoke cloture and end debate on the bill. Most Republicans voted against the cloture motion, though seven voted for it. And most Democrats voted for the cloture motion, though 11 voted against it. Of the three cloture votes called on this day, this last vote came the closest to being successful. But this motion was defeated as were the prior two cloture motions, and debate on the bill continued. However, because the majority was so unsuccessful in forcing a final vote on the bill, Reid declared the issue dead for the rest of the year and pulled it from the schedule.