MARSHALLTOWN, Iowa (AP) — Bernie Sanders insists he feels better than ever less than a month after heart surgery, but his return to the campaign trail this week sparked new questions about the unusually old age of the Democratic Party's leading 2020 presidential candidates.

Both Sanders, 78, and Joe Biden, 76, suggest their age isn't a major issue, but voters, particularly older voters, aren't so sure.

Gordon Lundberg, a 71-year-old retired Lutheran pastor from Ames, said candidates' health is a key issue for him because he understands how it feels to age. He's leaning toward Sen. Elizabeth Wa...