WASHINGTON — The Democrats have established their 2016 war room in a glassy new building in downtown Washington. The Republicans are setting up shop across the Potomac River in the Northern Virginia suburbs.

Long before any candidates announce their presidential bids, the next race for the White House is unofficially under way. Political operatives for two independent groups — American Bridge 21st Century on the left and America Rising on the right — are already tracking potential contenders, aiming to build robust research files that can be used against the opposition.

The organizations are part of a wave of super PACs, advocacy groups and even for-profit corporations that are poised to play their biggest role yet in national politics. They are launching opposition-research projects, mobilizing volunteers and even helping to recruit candidates — further eroding the primacy of the official party hierarchies in the process.

“We are going to continue to see the outsourcing of core functions of the DNC and RNC to outside groups,” said election-law attorney Robert Kelner, referring to the Democratic and Republican national committees. “By November 2014, there will be a true shadow political-party system in place on both sides of the aisle.”

The proliferation of independent players comes after such groups reported spending a record $1 billion in 2012. While their track records were mixed, their overall advantages are clear: Unlike parties and candidates, they can accept unlimited donations, can take money directly from corporations and unions, and, in many cases, are not required to disclose their donors.

Already, super PACs have kicked off the action in the 2014 midterm campaigns in places such as Kentucky, where Republican Senate Minority Leader Mitch McConnell’s bid for re-election has spurred a firefight on the airwaves between independent groups. And the conservative advocacy group Club for Growth is jumping into Republican primaries.

New super PACs are also accelerating the start of the 2016 presidential campaign, rushing to define candidates long before any of them actually get in the race. The Ready for Hillary super PAC has drafted top political strategists and fundraisers to help lay the groundwork for former Secretary of State Hillary Rodham Clinton. It was quickly followed by the establishment of several anti-Clinton super PACs, as well as two independent groups promoting the possible bid of Sen. Rand Paul, R-Ky.

The early activity reflects a consensus among political operatives that the most valuable money spent in 2012 came early in the cycle, before voters started tuning out the cascade of political attack ads.

But the growing clout of independent political players alarms party veterans, who say it makes consensus harder to achieve.

“It’s good for the lawyers, bad for the republic,” said Mark Braden, a former chief counsel to the RNC. “The party organizations have to be large, inclusive groups. Outside groups don’t have to. They tend to be more focused on single issues. It fragments parties and makes it harder to govern.”

Republican and Democratic officials argue that the current landscape makes the official party organizations more essential than ever. They are the only entities that can directly coordinate spending with candidates, and they have deep institutional investments in sophisticated get-out-the-vote operations.

“The breadth and scope of the work we do here at the DNC can’t be replicated,” said spokesman Michael Czin.

The Republicans plan to hire America Rising, which was set up as a private limited-liability company, allowing the group to sell its research to its related super PAC, as well as to candidates and party committees. As an LLC, it is not required to disclose its funders or other financial details.

Hiring the group “allows us to start something a lot earlier, keeping an eye on 2016 without bringing on the amount of people it would require,” said RNC spokesman Sean Spicer.

America Rising was a direct response to American Bridge, the Democratic-allied opposition-research super PAC that portrayed Romney as an out-of-touch plutocrat in 2012.

“In last cycle, you saw Democrats do a better job in investing in research and tracking,” said former RNC spokesman Tim Miller. “I think there was a feeling throughout the party that this was something that we needed to catch up in, both for 2014 and in preparing for 2016.”

Across the river, similar work is under way at American Bridge, which this month announced a new project called Correct the Record for defending potential 2016 Democratic contenders and compiling research on their Republican rivals.

Rodell Mollineau, the group’s president, said the effort is necessary to counter attacks on Democrats by House Republicans and pro-Republican groups such as America Rising and Crossroads GPS.

“I want to make sure that our folks have a little bit of breathing room and that potential Republican candidates don’t totally rewrite their story two years before an election,” he said.