An incipient sense of anxiety is tugging at some Democrats — a feeling tersely captured in four words from a blog post written recently by a seasoned party strategist in Florida: “Marco Rubio scares me.”
What is so unnerving to them at this early phase of the 2016 presidential campaign still seems, at worst, a distant danger: the prospect of a head-to-head general-election contest between Mr. Rubio, the Republican senator from Florida, and Hillary Rodham Clinton.
Yet the worriers include some on Mrs. Clinton’s team. And even former President Bill Clinton is said to worry that Mr. Rubio could become the Republican nominee, whittle away at Mrs. Clinton’s support from Hispanics and jeopardize her chances of carrying Florida’s vital 29 electoral votes.
Democrats express concerns not only about whether Mr. Rubio, 43, a son of Cuban immigrants, will win over Hispanic voters, a growing and increasingly important slice of the electorate. They also worry that he would offer a sharp generational contrast to Mrs. Clinton, a fixture in American politics for nearly a quarter-century who will turn 69 before the election.