WASHINGTON — The top US House Democrat warned Thursday that Republican lawmakers were "frivolously" going after Attorney General Eric Holder in a bid to suppress votes ahead of November's general election.

A House panel voted along party lines Wednesday to hold Holder in contempt for failing to turn over documents linked to a failed gun-smuggling probe.

Minority Leader Nancy Pelosi said she was alarmed that Republicans were using "contempt of Congress to frivolously use that really important vehicle to undermine the person who is assigned to stop the voter suppression in our country."

"This is no accident," she told reporters. "It is no coincidence. It is a plan on the part of Republicans" to monopolize Holder's time and "undermine his name" in the midst of a presidential campaign in which some states are grappling with claims of voter suppression efforts.

The US government filed a lawsuit last week seeking to block Florida's purge of voter registration rolls, claiming Florida was being discriminatory and violating national law by "conducting a systematic program to purge voters" from its lists.

Holder has led the fight against such voter suppression measures.

The row over the probe into Fast and Furious, the botched government operation in which agents knowingly allowed weapons to be smuggled across the border to Mexico in order to track arms flows to drug cartels, has simmered for more than a year.

But it shifted to the front burner Wednesday when President Barack Obama invoked executive privilege to withhold documents sought by the House Oversight Committee.

"The decision to invoke executive privilege is an admission that White House officials were involved in decisions that misled the Congress and have covered up the truth," House Speaker John Boehner told reporters.

"What is the Obama administration hiding in Fast and Furious?"

Boehner said he will bring the contempt resolution to a full House vote next week unless Holder produces the documents. Committee chairman Darrell Issa has said he hoped Holder would make the documents available to him.

Boehner said the claim of executive privilege "raises very serious questions" about how the administration handled Fast and Furious -- whose gun-running predecessor programs were launched during the Bush administration.

But he dodged the question of whether Holder should resign, saying only that "it's not about personalities."

Issa has been pressing the administration over why the Justice Department sent a letter to Congress in February 2011 which inaccurately stated that no weapons were "walked" across the border with US government knowledge.

He also wants to know why it took 10 months to retract that letter and who was involved in the deliberations.

The case has hit the headlines at a bad time for Obama who is locked in a tight race against Republican Mitt Romney.

Even though Pelosi insists Republicans are waging an election-year witchhunt, the oversight committee's ranking Democrat Elijah Cummings said that -- while he is discouraged by the contempt charge -- he doesn't see a broader scandal playing out.

"In the end, I think that when all the dust settles, this battle will be resolved," Cummings told MSNBC.