In the midst of the upcoming US presidential election against Donald Trump and JD Vance, Kamala Harris, the Democratic nominee, is set to reveal her choice of running mate within the next six to seven days, according to the influential Democratic campaign co-chair, Gretchen Whitmer. The announcement will coincide with the Democrats' national gathering in Chicago next month.

Whitmer, who is also the governor of Michigan, stated that she herself is not under consideration for the position and intends to fulfill her term as governor until the end of 2026. Harris has reportedly narrowed down her potential picks to three candidates, all of whom are white men from key states expected to play significant roles in the November election.

A recent poll conducted by ABC News and Ipsos revealed that among the three frontrunners, Arizona senator Mark Kelly was viewed most favorably by voters, obtaining a net favorability rating of +10. The two other contenders—Minnesota governor Tim Walz and Pennsylvania governor Josh Shapiro—garnered favorability scores of -1 and +4, respectively.

Vance, however, faced significant challenges in the poll's favorability ratings. The Ohio senator has been embroiled in controversy and faced criticism from Democrats. His unfavorability rating was the second highest in the poll, at -15, trailing only behind President Trump himself, who received a rating of -16. Vance has been targeted for making disparaging comments about leading Democrats and for his prior criticism of Trump, which has led to doubts among senior Republicans.

Although Kelly has gained a favorable rating, the poll also highlighted that he, along with most other potential Democratic picks, remains relatively unknown to a large portion of the American public. Among the possible Democratic nominees for vice-president, Pete Buttigieg, the transportation secretary, and Gavin Newsom, the governor of California, were the best-known to voters.

Candidates like Kelly, who represents a border state central to the immigration debate and is married to former congresswoman Gabby Giffords, known for her advocacy of gun control reform, are seen as potential assets to Harris. Another contender, Shapiro, hails from a rust belt state that played a crucial role in both Trump's victory in 2016 and Joe Biden's in 2020. Walz, whose state of Minnesota has consistently voted for the Democratic nominee since 1976, has been targeted by Trump's campaign this year due to polling gains before Biden secured the nomination.

As the countdown to the announcement continues, Harris' team is reportedly focusing on potential running mates' ability to effectively challenge Vance, whom they portray as ill-prepared to assume the vice-presidency if Trump were to be unable to serve a full term. Vance's lack of experience and controversial statements have led Harris campaign co-chair, Mitch Landrieu, to describe him as "one of the most unprepared people... ever put up to hold the vice-presidency of the United States."

Age has also become a prominent factor in this election, as Biden, at 81, withdrew from his re-election campaign due to concerns about his age. Trump, now 78, is officially the oldest candidate ever to run for the White House.

The running-mate selection process for Harris will be informed by her own experiences, according to an unnamed campaign advisor. Harris, a former California attorney general and US senator, has generated reports of struggles during her four years as vice-president but has also demonstrated effectiveness on key campaign issues, particularly in regards to abortion rights.

As Harris prepares to announce her running mate, her campaign spokesperson, James Singer, assured the public that the selection will be made with the American people's best interests in mind—to protect their freedoms and fight for their future. The anticipation grows as Harris' decision will have significant implications for the upcoming election and the future of the United States.