Congress is poised to approve a federal apology for slavery just weeks before voters consider electing the nation’s first black president.

When the Senate takes up the issue in September, it could address a centuries-old wound at a time when the presidential contest is already focused on race.

Sens. Tom Harkin (D-Iowa) and Sam Brownback (R-Kan.) have long been negotiating the upper chamber’s version of the 740-word House resolution, and Majority Leader Harry Reid (D-Nev.) plans to take it to the floor before the chamber adjourns on Sept. 26.

Reid spokesman Jim Manley said he thinks the chamber could get a unanimous consent agreement to move quickly on the measure.

The House passed its version of the resolution on July 29 by voice vote. Rep. Steve Cohen (D-Tenn.), a white lawmaker representing a majority-black district who faces a tough primary this week against a black challenger, is the lead sponsor of the resolution.

Critics have long cited the impracticality of legal or financial amends as the chief argument against apologizing, since an apology could increase demands for such reparations.

Mindful of those concerns, Harkin and Brownback’s Senate draft includes a key disclaimer that differs from the House resolution. The disclaimer: “Nothing in this resolution authorizes or supports any claim against the United States.”

Keith Wright, executive vice president and chief operating officer of the Congressional Black Caucus Foundation, said reparations aren’t necessarily tied to the idea of an apology. Wright says an apology would be “helpful to the healing process” for African-Americans.

“You can’t count up the cost of the system of slavery, so you couldn’t really pay for it,” he said. “Our argument is that an apology should stand on its own.”

But even without that provision, an apology has the potential to further polarize voters deciding between a black Democratic presidential candidate and a white Republican standard-bearer.