It’s a $6 billion election.

That’s the latest estimate for the cost of campaigning in all federal races by the nonpartisan Center for Responsive Politics, which released its newest calculations Wednesday afternoon. The total is up from $5.3 billion in 2008 and continues a pattern of steady growth in the cost of election politics in recent decades.

The big change in this election cycle is a shift to spending by outside political groups, including so-called super PACs. Overall, the presidential candidates themselves will spend less than they did in the blockbuster 2008 cycle, CRP said. But add in groups operating from the outside — often barely outside — and you've got a $2.6 billion cost for this year’s presidential contest.

That independent spending flowing to races at the last minute means that candidates will feel more pressure to defensively raise money for their campaigns, said Sheila Krumholz, director of the center. It has also prompted ads that are “more negative and more deceptive.”

“It only amounts to a small share of the funding, but it’s profoundly important,” Krumholz said.

That small share is still $1 billion — a “conservative” figure that doesn't include much spending through non-disclosing groups.