Parnes' partnership with fellow political correspondent Jonathan Allen resulted in two best-selling books on Hillary Clinton.

[5][6] She first became interested in political journalism while working as an intern for The New York Times in 2000, with her first major news story being the 2000 United States presidential election recount in Florida.

[3][10] In 2012, Parnes partnered with journalist Jonathan Allen of Politico to write a book on then U.S. Secretary of State Hillary Clinton that focused on her tenure and political future.

"[17] A widely publicized finding from Allen and Parnes' reporting was an enemies list compiled by Clinton's campaign staff in 2008.

[20] In April 2014, Crown Publishing Group officially announced that Allen and Parnes would collaborate on a book centered on Clinton's anticipated 2016 presidential campaign.

[22] The book received positive reviews from critics such as Michiko Kakutani of The New York Times and David Shribman of The Globe and Mail.

Carlos Lozada of The Washington Post wrote that the book "provides useful detail to understand Biden's victory, even if the framing is not particularly novel.

[6] After repeated requests and promises of a raise and four months of severance pay, Parnes left The Hill and began reporting for The Messenger once the site launched in May 2023.

[32][31] The lawsuit demands 60 days in unpaid wages, health and life insurance, accrued vacation time, and other employee benefits.

[35] In 2013, a photo taken of then Vice President Joe Biden embracing Parnes during a holiday party at Number One Observatory Circle went viral.

[36] Anchors Matt Lauer, Natalie Morales, Savannah Guthrie, and Tamron Hall of Today all defended Biden on air, arguing that the photo showed nothing inappropriate.

Reuters has reported on two separate edits of the photo that both circulated on Facebook, the latter of which replaced Parnes' likeness with that of then White House Press Secretary Jen Psaki.