New Grassley campaign ad leans into his age and seniority in the Senate, hailing him as the 'push-up pro' of America's gerontocracy

• Republican Sen. Chuck Grassley is running for an eighth term this fall.
• A new campaign ad highlights the 88-year-old Iowan's decades of service on Capitol Hill.

One reason Iowans should return 88-year-old Chuck Grassley to the US Senate for an historic eighth term is because he'll finally have the seniority crown all to himself, his campaign team trumpets in a new ad.

"If reelected, Chuck Grassley will have the most seniority in the entire Senate," according to Grassley's "Champion for Iowa" spot, featuring a montage of the Hawkeye State Republican going about his business on Capitol Hill.

Grassley, who is already the eighth-longest-serving senator in US history, stands to be the longest-serving senator in Congress once Democratic Sen. Pat Leahy of Vermont officially retires at the end of the year.

While Leahy previously said he knew it was time to "pass the torch" after 40 years in DC, Grassley told Insider he felt compelled to stick around because he enjoys "serving the people of Iowa."

Grassley's decision to stay put feeds into Insider's "Red, White, and Gray" project, which explores the costs, benefits, and dangers of life in a democracy helmed by those of advanced age. Veteran congressional staffers shared how sticky things can get on Capitol Hill for leaders who critics decide are past their prime.

The TV ad attempts to quash any notion that Grassley's lost a step, playing up his commitment to touring all 99 counties in Iowa every year and splicing in a clip of the octogenarian pumping out push-ups.

Grassley plays up his stamina as well, working in footage of his pre-dawn running routine into the reelection announcement he tweeted out last fall.