Ever get the feeling the candidate who is making other candidates worry the most is Marco Rubio? Your feeling is on the money.

On Sunday, Hillary Rodham Clinton relaunched her campaign, trying to tag Republicans by saying they are singing the old Beatles song “Yesterday” — a deliberate effort to turn Rubio’s own stinging charge in April that she was a “leader from yesterday” who “began a campaign for president by promising to take us back to yesterday” back on him.

Not to be outdone, on Monday, Jeb Bush officially began his run for the presidency with a passive-aggressive assault on Rubio that implicitly linked him with Hillary: “the Washington mess,” he said, cannot be cleaned up “by electing the people who either helped create it or have proven incapable of fixing it.”

Before Bush spoke at his own campaign event, a Jeb supporter named Don Graetz who worked with Rubio in the Florida state Senate was all aggressive and no passive — he referred to Jeb as “the Florida Republican who can win.” Guess who the Florida Republican who can’t win is supposed to be.

Bush’s event was deliberately Cuban in flavor and feeling, designed to try to neutralize what would appear to be Rubio’s natural advantage with the large number of Cubans who will vote Republican in that state’s crucial February primary.

Rubio might be the scion of an immigrant Cuban family, but Jeb speaks fluent Spanish and is a devoted convert to Catholicism, the faith professed by most Cuban-Americans.

The other unquestioned top-tier Republican candidate, Wisconsin Gov. Scott Walker, has his own clever take on Rubio that seeks to take him down a peg while praising him.

Walker privately speaks admiringly of the Florida senator and says he’d be sure he’d want Rubio . . . as his own vice presidential running mate.

As the debates get closer, you can be sure that if Rubio remains at or near the top of the leader board, rivals will target him before anyone else — with particular emphasis on his immigration-liberalization flip-flop. (He was for it until it became clear it was a no-go with Republicans on Capitol Hill, so he basically turned on his own bill.)

What is it about Rubio that makes him seem so formidable? After all, he’s a first-term senator, he doesn’t have a list of accomplishments to recite, his first major appearance (in a State of the Union response) garnered giggles for his on-air guzzle from a bottle of Poland Spring, and he has a boyish mien that makes him seem even younger than his 44 years.

Yes, as a 44-year-old, he can lay a powerful claim to being a voice of the future — but then, so can Scott Walker, who’s only three years older and has a more impressive record of achievement.

Yes, as a Latino himself, he might be able to make the kind of inroads that will cut into the Democratic advantage with Hispanics, but as his launch demonstrated, Jeb Bush might be able to do so as well.

No, what makes Rubio so frightening to others is, simply, that he is a freakishly gifted politician — and a daring one.

He chose to challenge the sitting governor of Florida, Charlie Crist, for the Republican nomination for Senate in 2009 when Crist was at 60 percent in the polls and he was at 3 — and not only knocked Crist out of the GOP race but then beat him by 20 points when Crist ran as an independent in the general election.

It was an unprecedented triumph, like a rookie pitcher winning 25 games, and only another politician knows just how seriously he must take a rival like that.

But here’s the real thing about Rubio. I’ve listened to him and watched him talk, both in private sessions and on the Senate floor in speeches you can see on YouTube.

He is, without question, the most naturally gifted off-the-cuff political speaker I have ever seen.

His fluency on subjects ranging from conflicts in the South China Sea to flexible community-college credits is, quite simply, dazzling.

His rivals will go after him with the charge that this is all glibness — and they may score with the charge. He’s a talker, they will say; I’m a doer. Still, most of campaigning is nothing but talk.

Speeches, interviews, debates; talk is what they do.

It’s better to be a good talker than a bad talker, and it stands to reason that it’s therefore better to be a surreally great talker than a good one.

I have no idea whether Rubio will prevail in the GOP primaries next year and I have no idea whether, if he does, he will beat Hillary. What is unquestionable is that she and other Republicans fear him above all others.