Political ad spending is surging for the U.S. election, with digital campaigns, led by Facebook, accounting for nearly one-fifth of the total, researchers said Wednesday.

A report by eMarketer predicted that total campaign media spending jumping 63 percent from four years ago to 6.89 billion U.S. dollars. Television will account for the largest share of political advertising at 4.5 billion U.S. dollars or 66 percent of the total, taking away some dollars from print and radio. 

"Despite cord-cutting and declining viewership, TV still offers strong reach, particularly among older Americans who are likely to vote," said eMarketer analyst Eric Haggstrom.

Digital political advertising in the current electoral cycle will likely reach 1.34 billion U.S. dollars for the first time, accounting for 19.4 percent of the total. Facebook is expected to take in nearly 60 percent of digital dollars, according to eMarketer, with 18 percent for Google and 22 percent for other online services.

Spending on digital political ads this election cycle amounts to more than three times the last presidential cycle, largely due to the large number of Democratic primary candidates, the research firm said. Those roughly two dozen candidates have spent millions to compile lists and acquire small donors, eMarketer noted.

The eMarketer analyst said the key benefit of digital advertising over TV is its targeting capabilities which can reach the right people with the right message efficiently.

"Facebook offers reach, targeting capabilities and ease of use that appeal to political advertisers," Haggstrom said. "Candidates can more quickly and easily send ads to potential supporters compared with TV or radio. In a competitive election, timeliness, efficiency and relevancy are incredibly important."

Online platforms have faced increasing pressure to curb political misinformation, including from candidate ads. However, Facebook continues to accept political advertising and has declined to impose as many restrictions as its competitors, including Google and Twitter.

"While Twitter has chosen to block political ads, and Google has chosen to limit the targeting of political ads, we are choosing to expand transparency and give more controls to people when it comes to political ads," wrote Rob Leathern, Facebook's director of product management, in a January 2020 blog post.

Despite the rejection of Facebook, an October 2019 CivicScience survey shows tactics the giant tech company taken may eventually leave its consumers unhappy. Fifty-seven percent of U.S. adult internet users said they strongly agreed that Facebook should ban political ads.

And in a separate study from November 2018, CivicScience found that 54 percent of U.S. Facebook users would "gladly do away with all political posts on Facebook" if they could.

(With input from agencies.)