"When they go low, we go high," former first lady Michelle Obama recited as her motto.
When it comes to electability, however, that could be bad advice — but not in the way that might be imagined.
Research into the voices of political candidates concludes how a contender speaks is critical — and lower pitch is better.
"Individuals with lower voices are more likely to win and to win a larger vote share," says University of Miami Associate Professor Casey Klofstad. "What our experimental data show is that we like candidates with lower voices, largely because they are perceived as stronger and more confident and, to a lesser degree, because they're perceived as older."
This tonal bias may partly explain the under-representation of women in elected office. And with a record number of women vying for the Democratic Party's nomination for U.S. president, the research is receiving wider scrutiny.
Stanford Gregory, emeritus professor of sociology at Kent State University, studied the voice characteristics of the U.S. presidential general election contenders between 1960 and 2000, as well as analyzing the three debates in 2008 between Democrat Barack Obama and Republican John McCain.
Gregory noted a tendency for McCain to show dominance in the lower nonverbal frequencies of his voice while Obama finished the debates more strongly.
Gregory and his Kent State colleague Will Kalhoff observed a "recency effect," in which potential voters take away more of an impression from the end of debates.
Obama had a "rope-a-dope" debating style akin to the boxing techniques of heavyweight legend Muhammed Ali who would hang back from the start of a fight until his opponent exhausted himself and then dominate the end of the match, according to Gregory who concluded the victorious candidate is the one who sets the tone, so to speak.
"We found it was the person who changed the least in his lower frequencies compared to the other person, so in effect from the beginning, he would set the lower frequency tone and the other person would adapt to that in the course of debates," says Gregory.
The effect also could be seen in the 2016 Republican primary where President Donald Trump, initially regarded as a longshot, overwhelmed as many as 10 candidates on the debate stage, including former Florida governor Jeb Bush and Senators Marco Rubio of Florida and Ted Cruz of Texas.
"It was just obvious this is what he did," states Gregory.
As Vox news editor Libby Nelson, also an adjunct professor of public affairs at American University, wrote, looking back on Trump's primary debates' performance: Trump would "pick out one or two antagonists during any given debate — always some combination of Bush, Marco Rubio, and Ted Cruz — to try to take down. The point wasn't to get them to concede a policy point to him, but to establish that Trump was the one who should be allowed to talk."
Some who work on campaigns cast doubt, however, on relying on such research to predict outcomes of races, especially for presidential contests where voters are more likely to more intensively scrutinize candidates.
"I'm skeptical as a practitioner of anytime someone comes and says, 'We have isolated the thing that impacts the results of a campaign'— whether it's yard signs, TV ads, money in politics or how someone talks," says Matt Dole, who has worked on about 250 local and state campaigns of Republican candidates in Ohio.
Dole tells VOA that voices "could have a role" in influencing voters, as might a candidate's gender, facial characteristics, height, attire and other cosmetic features.
Gregory was asked who among the large field of 2020 Democratic hopefuls might best set the advantageous low tone during the party's upcoming televised debates? (VOA)