The New Hampshire Senate race is projected to be a stalemate to the bitter end, with Democrats and Republicans searching for any advantage over each other’s widely popular and respected candidates to break open the contest.

Incumbent Sen. Kelly Ayotte and fellow Republicans in recent weeks have seized on new revelations about a supporter and contributor to challenger Democratic Gov. Maggie Hassan.

The supporter, Rick Schubart, was forced to retire in 2011 as a teacher from a prestigious New England prep school after admitting to sexual misconduct and was barred from its campus last year after admitting to a second allegation, which took place in the 1970s or ‘80s.

However, those admissions were not made public until late-March, as the result of a Boston Globe inquiry.

Schubart and his wife in 2012 gave $375 to Hassan’s gubernatorial campaign and reportedly were on a steering committee. Hassan told reporters that she “sensed something was wrong” when Schubart left Phillips Exeter but didn’t know about the specifics.

The situation is further complicated by the fact Hassan’s husband, Tom Hassan, was the school principal when Schubart admitted the misconduct but until now never informed the public.

Gov. Hassan has more recently said that she should have “worked more actively” to review her public-supporter and steering committee lists and remove Schubart from it.

“I apologize for that,” she told the local news media. The Hassan campaign did not return a request Saturday for comment.

The race became a tossup essentially since the day Hassan announced in October 2015 that she would challenge Ayotte’s bid for a second term.

The Cook Political Report, in fact, said the race is destined to remain a statistical tie through November “barring a monumental mistake by one candidate or the other.”  

However, neither the Cook nor the Rothenberg Political Report -- two of the most respected, non-partisan congressional race handicappers -- have release an analysis of the Ayotte-Hassan race since the new Schubart revelations.

“Ayotte is sitting at the center of what is shaping up to be one of the most epic battles of the cycle,” the Cook analysis in October said. “Democrats scored their biggest recruiting coup thus far when … Hassan announced that she would run. The result is a contest between the two most popular politicians in the state.”

The winner will likely determine which major political party controls the Senate, as Democrats try to win four or five seats in November to take the upper chamber from Republicans.

“The matchup is set for one of the most competitive Senate races in the country,” said the Rothenberg analysis in early March. “Both women started the race with high name identification, positive images and good job approval numbers. But time will tell how well they hold up.”

Ayotte appears to have so far avoided any major controversy but faces at least one on Capitol Hill that Democrats continue to spotlight, her support for Senate Majority Leader Mitch McConnell saying no confirmations hearings for President Obama’s Supreme Court nomination, Merrick Garland.

Ayotte said Thursday the Schubart controversy raises "important" concerns and that more questions must be asked, especially since Hassan seems to have given a couple of different answers.

“We should be focusing on: What was the student body told and why wasn’t the student body fully informed?” Ayotte said in a statement.

The National Republican Senatorial Committee has been among the first to seize upon the controversy for a political advantage, saying Hassan is giving an “evolving story” and that she “owes voters an explanation.”

Hassan said she’s returning the campaign contribution by giving $1,000 to a charity and that she and her husband, who has also apologized, have jobs in which they have to keep some things confidential, “even within the marriage.”

Tom Hassan told WMUR-TV through a spokesman that his school administration should have been more “transparent” and that it failed to “balance the privacy and wishes of the victim with the utmost need to ensure the safety of members of the community.”