Question: What is the birth date of the former Trump campaign manager who promoted Jack Posobiec's tweets?

Context articles: Rick Davis (politics)
Our Principles PAC
Basket of deplorables
Thomas D. Singleton
Hippolytus (archbishop of Gniezno)
Roger Stone
Astro Boy (2003 TV series)
Jack Posobiec
Robby Mook
Jack Little (songwriter)

Richard H. "Rick" Davis, Jr. (born 1957) is an American political consultant.
 He currently serves as a Partner and Chief Operating Officer of Pegasus Sustainable Century Merchant Bank, a private equity firm specializing in sustainable development projects.
 He is a managing partner of the business development and public affairs consulting firm Davis-Manafort, located in Alexandria, Virginia.
 He is best known for being the National Campaign Manager of John McCain's 2008 Presidential campaign (from April 25, 2007 to November 4, 2008).
 In that capacity, he oversaw the development and implementation of all campaign strategy and policy development.
 Davis also served McCain as National Campaign Manager for his 2000 Republican Presidential Primary campaign ( April 6, 1999 to March 9, 2000).
Our Principles PAC was a super PAC established in January 2016.
 Its goal was to oppose Donald Trump's campaign for president.
 Our Principles PAC was led by Katie Packer, who was deputy campaign manager of Mitt Romney's 2012 campaign.
 The month of the Iowa caucuses, the group sent out mailers to voters in the state, attacking Trump.
 In March, it released a video attacking Trump, featuring women reading some of his sexist statements about women.
"Basket of deplorables" is a phrase from a 2016 presidential election campaign speech delivered by Democratic nominee Hillary Clinton on September 9, 2016, at a campaign fundraising event, which Clinton used to describe a faction of supporters of her general election opponent, Republican nominee Donald Trump.
 Clinton later said that she "regrets saying half [of Trump's supporters]", and the Trump campaign repeatedly used the phrase against her during and after the 2016 presidential election.
 Many Trump supporters adopted the "Deplorable" moniker for themselves.
 After Clinton's loss, some journalists and political analysts questioned whether or not the speech played a role in the election's outcome.
Thomas Day Singleton (Birth date unknown – November 25, 1833) was a United States Representative from South Carolina.
 He was born near Kingstree, South Carolina but his birth date is unknown.
Hippolytus or Hipolit (died c. 1027) was an early medieval archbishop of Gniezno.
 His place and date of birth date are unknown but the medieval historian Jan Długosz claims that he was of noble birth and a Roman citizen.
 Modern scholars generally agree that he was not Polish.
Roger Jason Stone Jr. (born August 27, 1952) is an American political consultant, lobbyist, and strategist, noted for his use of opposition research usually for candidates of the Republican Party.
Astro Boy (アストロボーイ・鉄腕アトム , Asutoro Bōi: Tetsuwan Atomu , lit.
 "Astro Boy: Mighty Atom") is a remake of the 1960s anime series of the same name created by Osamu Tezuka, which was produced by his company, Tezuka Productions, Sony Pictures Entertainment Japan, Dentsu, and Fuji Television network.
 It was also shown on Animax, who have broadcast the series across its respective networks worldwide, including Japan, Southeast Asia, South Asia, East Asia, and other regions.
 It was created to celebrate the birth date of Atom/Astro Boy (as well as the 40th anniversary of the original TV series).
 Under the original English name (instead of "Mighty Atom"), it kept the same classic art style as the original manga and anime, but was revisioned and modernized with more lush, high-quality, near-theatrical animation and visuals.
 It combined the playfulness of the early anime with the darker, more serious and dramatic Science fiction themes of the manga and the 1980 series.
 The anime broadcast in Japan on the same date as Atom's/Astro's birth in the manga (April 6, 2003) across Animax and Fuji Television.
 It was directed by Kazuya Konaka and written by Chiaki J. Konaka at the beginning of the series.
 Other writers included were Keiichi Hasegawa, Sadayuki Murai, Ai Ohta, Hirotoshi Kobayashi, Kenji Konuta, and Marc Handler, who was also executive story editor.
Jack Posobiec ( ) is an American alt-right pro-Donald Trump Internet activist and conspiracy theorist, known primarily for his controversial comments on Twitter.
 During the 2016 election, he was a special projects director of Citizens for Trump, a pro-Trump organization.
 For two months in 2017, he was a correspondent for "The Rebel", a far-right Canada-based website.
 He was granted press access to the White House in April 2017, and his tweets have been promoted by former Trump campaign manager Roger Stone.
Robert E. Mook ( ; born December 3, 1979) is an American political campaign strategist and campaign manager.
 He was the campaign manager for Hillary Clinton's 2016 presidential campaign.
Jack Little (born John Leonard; May 30, 1899 – April 9, 1956), (Another source gives his birth date as May 28, 1902.)
 sometimes credited Little Jack Little, was a British-born American composer, singer, pianist, actor, and songwriter whose songs were featured in several movies.
 He is not to be confused with the burlesque comedian also known as "Little" Jack Little, who stood 4'5".