Seniority was once valued in politics, but this year, incumbents are having trouble convincing voters that politicians get better with age. 

It’s an issue that was front and center last week in 76-year-old Sen. Thad Cochran’s (R-Miss.) primary runoff battle with state Sen. Chris McDaniel, and was a driving force in 91-year-old Rep. Ralph Hall’s (R-Texas) loss last month. 

For both Hall and Cochran, it’s not just that their decades of service are seen as a detriment — questions about the effects of their age are popping up, too. 

Cochran might have given his detractors more fuel for those charges over the past few weeks. After giving an interview on Wednesday commenting on House Majority Leader Eric Cantor’s (R-Va.) stunning primary loss last week, Cochran, in a separate interview on Thursday, seemed unaware of the upset or its significance. It was one of a series of such moments in the race during which Cochran appeared confused or forgetful concerning campaign issues.

Though McDaniel’s team hasn’t overtly pushed the issue, Cochran’s own comments have made it hard to ignore, even prior to his statements on Cantor last week.

Ford O’Connell, a GOP strategist who has worked in Mississippi before, said that McDaniel’s team has to be careful in how it uses the issue in the race, lest it provoke some “sympathy votes” for the well-liked Cochran. 

But McDaniel’s team hasn’t had to mention it outright, because Cochran, unlike Hall, has drawn negative attention to the age issue with his own comments. 

And it’s there that the incumbent could make the argument for McDaniel’s team, O’Connell said. 

“That is precisely the connection that the McDaniel campaign wants Mississippi runoff voters to make — the idea is, Thad’s a good guy; he’s served well, but it’s time to turn over the reins,” O’Connell said.

Read more from Alexandra Jaffe at The Hill

In two hotly contested primaries, age is creeping into the narrative and raising the specter of “ageism” as voters prepare to go to the polls.

In Texas, the oldest member of Congress – Rep. Ralph Hall (R) – faces a primary challenger 43 years his junior in a runoff next Tuesday, and the issue is starting to bite. Former US attorney John Ratcliffe said Thursday that he thinks age is fair game in the campaign to unseat Congressman Hall, who is in his early 90s.

In Mississippi, six-term Sen. Thad Cochran (R) is in his mid-70s – a spring chicken, by the Senate’s historical standards – but he’s still fighting his primary opponent’s story line that it’s time for new (read: younger) blood. Senator Cochran is also facing allegations he’s avoiding public appearances back home.

What’s more, Cochran’s opponent, state Sen. Chris McDaniel, is embroiled in a controversy over the actions of a supporter who allegedly photographed Cochran’s bedridden wife in her nursing home and posted a video online (since removed). The supporter has been arrested and faces felony charges. Senator McDaniel says he and his campaign had nothing to do with the actions of the supporter, a blogger named Clayton Kelly. The Cochran campaign is raising questions about the McDaniel camp’s denials.

Though the photos were of Cochran’s wife, the intent of the video was “clearly to make Cochran look like an old man,” says Republican strategist Ford O’Connell.

Read more from Linda Feldmann at The Christian Science Monitor