The American Crossroads super PAC and and its nonprofit arm are unlikely to engage in the GOP presidential primaries in 2016, opening the door for another chaotic fight akin to what happened in 2012.

Final plans for the super PAC and its sister group, Crossroads GPS, are not yet firm. After this year’s midterms, Crossroads will engage in a “fresh assessment of how we fulfill our goals and targets,” chief executive Steven Law said in an interview last week.

But, he added, “I think it’s unlikely we would be involved in the presidential primary.”

Crossroads was the biggest player in the 2012 elections, spending $306 million between its super PAC and nonprofit. But it did not intervene in GOP primaries, pouring most of its political resources into an effort to prevent President Obama’s reelection.

Meanwhile, the contenders for the GOP presidential nomination engaged in a drawn-out, expensive primary fight, fueled in part by individualized super PACs that sprung up to support the various candidates.

The crossfire could be more intense in 2016, when as many as a dozen Republican candidates could be vying for the nomination.

Crossroads extensively recalibrated its approach to this year’s congressional races after feedback from donors dissatisfied with their return on investment in 2012. The group jumped into several primary fights, invested more in data analytics and opposition research and expanded its digital and mail communications.

Its strategy in 2014 is “highly specific to each state in which we’re engaged,” Law said. “It is not a cookie-cutter approach.”

Much of Crossroads’ funding is coming in the final months of the election, a sign of how donors who were dissatisfied with their return on investment in 2012 are dictating the action of GOP allies this year. Meanwhile, outside groups on the left led by top advisers to Senate Majority Leader Harry Reid have mounted an early, coordinated effort to defend Senate Democrats.

“I think Harry Reid was able to make a cogent argument earlier that the Senate majority was under siege and needed to be defended,” Law said. “On our side, the reality that the Senate majority was vulnerable crystallized later.”

“Not only were they able to raise money earlier, but they spent money earlier to try to bend these races in their direction,” he said.

Crossroads is responding with a major air assault in the final weeks before election day. Together, the two groups have already purchased more than $26 million in TV ad time in October in states such as Alaska, Arkansas, Colorado, Iowa, New Hampshire, Louisiana and North Carolina.

Buying late costs a major premium for ad time, but Law said he is confident that GOP allies have enough resources to get their messages across.“I wonder if we’ll conclude at the end of it all that some of that early spending washed in and washed out with the tide,” he said.

Law confirmed that a little less than 75% of the $100 million that Crossroads is set to bring in this cycle has been donated to its tax-exempt side -- a bigger share than in 2012.

That means campaign finance reports will not show the full extent of the organization’s reach. As a 501(c)(4) “social welfare” organization, Crossroads GPS does not have disclose its donors or report all of its spending to the Federal Election Commission.

The tilt in giving to Crossroads’ nonprofit arm shows how many conservative donors this year eschewed political committees that disclose their financial backers as Reid and other Democrats have pounded billionaire industrialists Charles and David Koch for their political activities.

"Certainly the Harry Reid attacks from Senate floor were designed to intimidate people and to get them not to exercise their First Amendment rights," Law said