Shelby, 83, has had his differences with Trump. He publicly opposed a GOP nominee backed by Trump in Alabama’s closely watched Senate race last year, declaring before the election that “the state of Alabama deserves better” than Roy Moore, a former judge accused of sexual contact with teenage girls decades ago.

Romney has the stature to make similar declarations when — or if — they are needed, Shelby said. “I know the governor and I think he would support good ideas,” Shelby said.

Romney, a heavy favorite to win the Senate seat, will step in “immediately” as a leader in the Senate, said Idaho Sen. Jim Risch, who got to know Romney when both served as governors and when he co-chaired Romney’s presidential campaigns in Idaho.

“He has broad experience, he has the prestige. He’ll jump right in,” Risch said.