But Republican strategists and pollsters say Democrats should not be so quick to brush off the criticism, even if many Covid-related deaths this year were among those who ignored Mr. Biden’s entreaties to get vaccinated.

“McCarthy’s first hit on Biden is a competence hit — that he sold himself to voters as the guy who can make a difference in the fight against Covid, yet more Americans are dying,” said Neil Newhouse, a Republican pollster who has surveyed voters on the issue. “The bottom line is that Republicans have always been more focused on the economic impact of the pandemic, and now we’re seeing independents and swing voters expressing concern about those impacts as well: supply chain, inflation, jobs, stores not being open or having what they need.”

He added, “There is a sense that Biden’s presidency is falling short on its promises.”