The long-awaited report on the controversial gun-trafficking operation known as Fast and Furious may be issued by the Justice Department inspector general as early as Wednesday.

The botched investigation was designed to track trafficking kingpins responsible for illegal gunrunning to Mexico. It has been blamed for contributing to crimes — including the high-profile slaying of a U.S. border agent — and has become a partisan bone of contention heading into the November elections.

The report is important because of its scope — it is the result of more than a year of research — and for its conclusions, which could stir even more partisan attacks, depending on its outcome. The report is expected to conclude whether the botched plan was mostly the doing of agents in Arizona, or if the Obama administration played a central role.

In the controversy over its handling, conservative Washington legislators voted down party lines to cite the U.S. attorney general — a Democrat — for contempt. It marked the first time in American history that the head of the Justice Department has been held in contempt by Congress.

Democrats protested the vote vehemently as being purely political.

What was Fast and Furious and what went wrong?

The Bureau of Alcohol, Tobacco, Firearms and Explosives — in cooperation with legal gun dealers — traced weapons of low-level buyers, who they believed were acquiring them illegally for Mexican drug cartels.

Hundreds of firearms from the program went missing, some turning up at killing scenes in Mexico — and at the site of a December 2010 gunbattle in Arizona that left U.S. Border Patrol agent Brian A. Terry dead.

Two senior ATF officials familiar with the report yet to be released have told CNN the findings are consistent with what ATF headquarters has maintained throughout the investigation — that much of the blame lies with officials in Phoenix who developed the operation and largely kept Washington executives in the dark.

The officials insisted upon anonymity, saying they were not allowed to comment on the draft report.

ATF officials in Arizona, however, have said they were following guidelines from headquarters.

U.S. Attorney General Eric Holder has said he will await the report to decide what disciplinary actions he will take against those determined to be responsible for the flawed investigation.

There has been at least one high-level resignation and a number of reassignments in Arizona in the wake of Fast and Furious.

Did ATF intentionally let guns ‘walk’ to cartels?

Terry’s tragic death put the public spotlight on Fast and Furious, and allegations surfaced that ATF officials intentionally did not intercept guns bought by straw buyers before they got into the hands of drug cartels — as a tactic intended to lead to bigger fish. Critics have said the alleged practice allowed guns to slip into the hands of the U.S. border agent’s killers.

In an interview with Fortune magazine published by CNN Money, agents have denied the existence of such a method.

“Just the opposite: They say they seized weapons whenever they could but were hamstrung by prosecutors and weak laws, which stymied them at every turn,” Fortune wrote.

How are Washington politics involved?

Republicans have used the issue to attack Holder and the Obama Justice Department, which is in charge of the ATF.

Congressional investigators issued a subpoena for documents from Holder relating to Operation Fast and Furious, and President Barack Obama asserted executive privilege over the documents.

The Republican-led House of Representatives, along with a handful of Democrats, voted to cite Holder for contempt. The vote along party lines was followed by the House taking the contempt issue to court, where it is expected to linger until well after the presidential election.