Brown’s campaign on Thursday released to the press copies of a written exchange between the two camps over a proposal by Brown’s team for a deal on access for trackers.

The proposal stemmed from a recent altercation at Mandel’s official campaign kickoff between a Brown tracker and a member of Mandel’s campaign staff. According to local media reports, the staff member attempted to physically block the tracker from filming Mandel’s appearance at the Akron Press Club, where audio and video recording are freely permitted.

Brown’s team pointed to other instances in which Mandel has been accused of blocking trackers from events and said the Akron scrap was further evidence that Mandel isn’t transparent and is trying to hide aspects of himself from voters.

Mandel’s campaign accused Brown and his tracker of trying to disrupt Mandel’s events, which Brown's camp denied.

The use of trackers to document what opponents do and say on the trail is nothing new. It has become something of an afterthought in an era when anyone can discreetly capture video on a cell phone.

And when candidates try to intervene, it rarely goes well. In 2006, former Sen. George Allen's (R-Va.) garnered national headlines after using the word “macaca” to refer to his opponent’s tracker, who was filming him. (Allen lost reelection that year but is making a comeback bid in 2012.)

After the Akron Press Club incident, Brown’s campaign requested the two sides strike a bipartisan deal to regulate access, similar to the outside-spending agreements that have popped up this cycle in Massachusetts and elsewhere. Brown campaign manager Sarah Benzing laid out the terms of such a proposal in a letter last week to Mandel campaign manager Ray Yonkura.

“In order to help accommodate the busy schedules of working families across the state, I’m proposing we make both Sen. Sherrod BrownSherrod Campbell BrownSenate campaign fundraising reports roll in Commerce sends Trump long-awaited steel report GOP Rep. Jim Renacci announces Ohio Senate bid MORE and Treasurer Josh Mandel’s public events more accessible,” Benzing wrote.

Benzing proposed that both candidates allow “opposition campaign staff” to be at all open-press events, rallies and office openings. She proposed that trackers be allowed to stand on the sidewalk outside fundraisers, and that trackers should have to identify themselves but not pay entrance fees for events. Trackers would be prevented from entering fundraisers or following candidates while they spend private time with their families.

“Thank you for your letter!” Yonkura wrote in response. “I have no doubt that your operatives will continue to attend and disrupt as many of our campaign events as they can, whether we sign this agreement or not.”

Yonkura said the campaign would be happy to negotiate the terms of an agreement — but only if Brown agreed first to three unrelated stipulations.

Yonkura insisted that Brown must “end the partisan bickering” by passing a budget through the Senate, “break with radical environmentalists” by supporting drilling in Ohio and elsewhere, and “reverse the unprecedented federal expansion into the private sector” that has shipped U.S. jobs to China and other countries.

Mandel and his campaign have accused Brown of shipping jobs to China and of siding with environmental extremists before. The nonpartisan Politifact rated both of those claims as “pants on fire.” On the issue of Democrats not passing a budget, Politifact has deemed similar statements by other Republicans to be half-true or mostly false.

Benzing shot back with a letter Tuesday calling Mandel’s decision not to take the proposal seriously “a disservice to Ohioans who deserve to hear from both candidates.”

Mandel's campaign said that discussing the issue further would distract from the real issues facing Ohio voters.

"As to the Brown campaign releasing the letters publicly: SHOCKER," a Mandel spokesman said.

A Quinnipiac University poll of the race released Thursday showed that Mandel is closing the gap on Brown, but Brown still leads by 10 points. The Hill rates this race as leaning Democratic.

- This post was updated at 3:25 p.m.