People who find political advertising annoying are going to have an increasingly difficult time escaping it as the 2016 presidential election draws near.

Total ad spending by political candidates running for anything from president to dog catcher is expected to top $12 billion in 2016, a gain of more than 22 percent from 2012, according to preliminary data from Borrell Associates due to be released later this week.

The majority of the spending -- 55.6 percent -- will go to broadcast TV, a gain of 19 percent over the past four years and equaling $6.5 billion. CBS Corp. (CBS), the parent of CBS MoneyWatch; Tengna (TGNA), the recently spun-off broadcast assets of Gannett; and Graham Holdings (GHC) are among the owners of local TV stations that will reap the benefits of this bonanza.

Cable networks will profit as well, pulling in $1.2 billion, an increase of 39 percent over 2012. Campaigns, though, are shifting some of their ad spending online, which will equal $955 million in 2016, a gain of nearly 500 percent since 2012, according to Borrell.

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Signs of the unprecedented level of political advertising abound. Sen. Marco Rubio's presidential campaign surprised political observers recently when it recently decided to buy advertising on local TV stations in key states such as Iowa, New Hampshire and South Carolina that won't be shown until February.

According to Borrell Associates research head Kip Cassino, no other campaign had ever made such a large ad buy so early in the electoral process. A Rubio campaign aide said the buy was preliminary and more were in the works.

Rubio isn't alone. Democrat Hillary Clinton recently shelled out $7.7 million to acquire spots in New Hampshire and Iowa, according to her staff.

"You are going to see messages popping up all over the place," Cassino told CBS MoneyWatch, adding that they might even appear in movie theaters. "Certainly, there will be more use of cable this time then there has been simply because there are just only so many 30-second spots that you can buy."

At least half of the spending increase is the result of the Supreme Court's controversial 2010 Citizens United decision, which made it tougher to restrain spending in the electoral process, according to Cassino. The politically conservative Koch brothers, who are billionaires, are said to be planning on spending $900 million on the 2016 campaign. Democratic-affiliated group such as unions will also open their checkbooks this election season.

Many of these ads are going to be negative, which may alienate voters even further after turnout in the 2014 midterm elections hit a low not seen in 70 years.

"The share volume of the money that's going to be spent and the sources from which it will be raised are causes of great concern," said Miles Rapoport, president of Common Cause, in an interview. He likened the current state of campaign finance to the "Wild West."

"Campaign contributions or campaign-related contributions in the millions of dollars or even the tens of millions of dollars are at play," Rapoport said. "That gives the people who can give those contributions enormous weight in the process that is completely undemocratic on its face."

Borrell's numbers differ from data recently released by Kantar Media, which forecast that TV advertising in the 2016 election would rise 16 percent to $4.4 billion compared with four years ago.

Kantar's Elizabeth Wilner, however, noted the difficulty with such forecasts. She wrote in the Cook Political Report, "...trying to project total 2016 TV ad spend before the end of the Republican presidential primary may just be a fool's errand."

Still, you can bet it will outstrip 2012 spending by a long shot.