I think this is more than just one popular senator endorsing a candidate.

He is a popular senator.

He was a wildly popular senator, and his party needed a presidential nominee.

Mark Pryor, the Democratic state attorney general and son of a popular former senator, has a slight edge, according to recent polls.

Reed was an extremely popular senator who got token opposition in the general election.

Robert Hawkins Grant, a popular Republican senator from Georgia, is coasting toward re-election when things suddenly start to go wrong.

As is often the case when a one-term representative runs against a popular incumbent senator or governor, Walker was soundly defeated.

Hall won the senate seat easily, and by 1998 his well-voiced position on crime had made him the most popular first-term senator in America.

That puts her approval rating even higher than that of New York's popular senior senator, Charles Schumer.

Shelby, who switched from Democrat to Republican in the mid 1990s, has been a popular senator in Alabama for three decades, first elected in 1986.