If the anti-human-trafficking legislation moving through the U.S. Senate eventually gets a vote, it will likely include provisions to beef up background checks for school employees.

But those provisions probably won’t come from an amendment offered by Sen. Pat Toomey, R-Pa., who has been pushing the issue and his bill, the Protecting Students from Sexual and Violent Predators Act, for years.

Education groups, including the two national teachers’ unions and AASA, the School Superintendents Association, and a slew of civil rights groups, have been lobbying senators all week to oppose Toomey’s proposal and instead support a background check amendment from Sen. Lamar Alexander, R-Tenn.

“While the Toomey amendment is well-intentioned, it fails to take steps to truly protect students or implement best practices to strengthen the background check system as a whole,” wrote the National Education Association in a letter sent to senators Tuesday. “In contrast ... the Alexander amendment [as well as another from Sen. Sheldon Whitehouse, D-R.I.] methodically address issues and effect improvements in the background check process—everything from preventing backlogs and ensuring the accuracy of FBI criminal records to providing a robust appeals process and protecting confidentiality.”

What’s more, Alexander took to the Senate floor Wednesday evening to urge his colleagues to support his amendment over Toomey’s, which he said would only bolster the U.S. Department of Education’s role as “a National School Board,” one of the Tennessee Republican’s favorite phrases.

So what’s the deal with Toomey’s amendment?

Toomey’s proposal, which he is offering with Sen. Joe Manchin, D-W.Va., would require schools to perform background checks on all new and existing employees and forbid schools from hiring people who have been convicted of certain crimes, including but not limited to any violent or sexual crime against a child. The measure, which the House passed last October, would also ban schools from “passing the trash"—the practice where a school allows a known child molester to resign quietly and helps that person find a new teaching job.

Education groups argue that specific provisions in the amendment would constrain schools’ ability to hire, and would create costly and redundant paperwork.

The amendment “poses not only unnecessary barriers to employment and unprecedented burden on school employers, but does so without providing greater protection for students,” wrote Noelle Ellerson, the associate executive director of policy and advocacy at AASA, in a letter to senators Wednesday.

Civil rights groups, some 42 of them, aired similar grievances in a letter also sent to senators on Wednesday.

“Individuals who have been convicted of crimes and have completed their sentences should not be unnecessarily subjected to additional punishment because of these convictions, and should only be excluded when safety is truly impacted,” the wrote.

Meanwhile, some Republicans, including Alexander, focused more on the power it would hand over to the federal government.

In his remarks on the floor, Alexander said it “would be the most extensive federal takeover of local school personnel decisions in our country’s history.”

Toomey railed back against those assertions during his own floor speech on Wednesday, arguing that the protections his amendment would provide are no different than the requirements in the Child Care Development Block grant that Congress passed at the tail end of last year.

“Why would we block providing comparable protection to kids that are just a little bit older,” Toomey asked. “How can it be that we want to make sure pedophiles don’t get into our day care centers, but it’s ok for them to be in elementary and middle and high schools? This makes no sense at all.”

Alexander pointed out on the Senate floor Wednesday that CCDGB is a preschool voucher program funded 100 percent by the federal government and therefore the federal government has the right to demand whatever specific background checks they want. (Actually, there’s a big state match requirement in CCDBG.)

On the other hand, Alexander argued, the federal government only provides 8 to 10 percent of funding for the K-12 public school system, so it shouldn’t have control over those specifics.

So how is Alexander’s proposal different?

Alexander’s amendment has all the same intentions as Toomey’s in that it would require criminal background checks for all school employees, but it would allow states and districts to do so in their own way, including, for example, choose which registries it uses. It would also authorize new funding and allow states and districts to tap existing federal funding in order to strengthen online registries and provide training to staff so that they can better identify students who are most at risk for such abuse.

Alexander’s amendment also takes into account several suggestions from a 2014 Government Accountability Report.

Whitehouse also has a background check amendment that would, among other things, specify which crimes should bar employment; initially limit background checks to new or current employees who haven’t already passed a state-mandated background check; and require states to prohibit withholding information about allegations of child abuse in school settings.

Let’s take a time-out to acknowledge the elephant in the room ...

Alexander is working with Sen. Patty Murray, D-Wash., to craft a bipartisan rewrite of the No Child Left Behind Act. The NEA, the AASA, and the American Federation of Teachers (which is slated to write to senators Thursday) would be silly not to back Alexander’s background-check amendment.

Also, it’s worth pointing out that this is not the first time Toomey has hit a roadblock pushing his bill. Last year, he essentially held the Child Care Development Block Grant bill hostage, demanding a vote on his background check bill before the Senate approved the overarching early-education legislation.

So what’s next?

Well, all of this is a moot point if the Senate can’t clear the 60-vote threshold, which looks unlikely at this point.

As my friend Niels Lesniewski reported in Roll Call Wednesday, Senate Minority Leader Harry Reid, D-Nev., emphasized that the anti-human-trafficking bill will not get through the Senate without the removal of language that would bar federal funding for abortion services.