For instance, the data, from Tremor Video and Cygnal shows that both millennials and Hispanics are twice as likely to be motivated by online video to register to vote, with Hispanics being 25% more likely to be influenced by video, specifically when it comes to deciding who to vote for.

"The findings were clear; both millennials and Hispanics are much more receptive to digital video advertising than the general population," said Ariane Gut, head of insights and analytics at Tremor Video. "But they're also less avid followers of political news. For this reason, it's essential for political advertisers to fully understand how these desirable audiences consume political video and what their triggers are in order to truly influence them."

Although smartphones play a pivotal role when consuming political video content and ads, both millennials and Hispanics leverage all screens, the study found. So political marketers should develop media plans and creative assets for all digital devices. While research suggests that millennials' consumption of political ads is typically in line with the general population's, Hispanics jumped out as being the audience that will require political advertisers to employ a multichannel approach (22% more likely to use tablets and 90% more likely to use connected TV).

"In politics, the millennial and Hispanic demographic groups have emerged as a significant influence in the last two cycles," said Cory Brown, VP of data and strategy at Cygnal. "A lot of effort and resources are going into reaching these groups and engaging them. This research shows the outsized effect online video has with these groups, and it's only increasing in its effectiveness to persuade them to action."

The findings suggest that political advertisers could benefit from leveraging the specific strengths of digital and go beyond repurposed TV ads. While the general population may not always be inclined to click on a video ad, both millennials and Hispanics are more than 40% more likely to do so. In fact, four in 10 millennials would want the ability to watch more related content when viewing a political video ad, and more than half of Hispanics feel the same.

Millennial and Hispanic survey respondents also show a proclivity for interacting with political ads, with nearly 30% of each audience agreeing that the ability to engage to learn more is important. This highlights the importance of creating video ads that not only inspire interaction, but also offer the ability to go deeper with the candidates and issues.

The ability to "learn more" is key especially for millennials, who are twice as likely as the general population to vote for a specific candidate or issue after being exposed to a political video ad. They are also 40% more likely to use digital videos as a political research tool. Conversely, they are 24% less likely to rely on TV.

Hispanics meanwhile are 24% more likely than the general population to use digital video as a tool for political research.