Many have wondered why Senator Marco Rubio, a Miami native, has remained so popular, after careful research it's become clear that the qualities that keep Rubio Relevant are the same ones that skyrocketed one Scooby "Dooby" Doo to popularity some 40 years ago.
They're both cowards
Scooby-Doo's cowardice is one of his defining traits. He runs from every problem that he faces, whether it be a ghost, a monster, or personal responsibility. Scoob's cowardice is insidious however because the moment the gang needs him to take a stand Velma simply has to give him a "Scooby-Snack" and suddenly he is impassioned and brave.
Marco is similarly a coward running away from things he claims to care about, like immigration reform. He often tries to hide in the proverbial van, and will often miss days on Capitol Hill to avoid scary legislation. Technically, this means Fred is a better negotiator than Mitch McConnel but that's neither here nor there. The only ones that know how to get Marco going are the lobbyists with their vast amounts of snacks. The NRA alone has given Rubio over 3 million Scooby-Snacks. Zoinks!
They both believe in consolidating wealth at the top
It's no secret that Senator Rubio supported the Republican tax plan that passed this December. The bill basically allows for the rich to suck up cash from the lower classes by funneling it through their own holdings. In much the same way Scooby-Doo uses his straw to suck up his friends', who do all the real work to contribute to Scooby's success, milkshakes. Scoob at least is honest and direct with his theft, using his own tongue to steal his friend's sandwiches. Marco, on the other hand, would steal Daphne's pig to give to the butcher, in hopes of maybe receiving one pan con lechon.
They are both totally divorced from their ethnicity
It's a well, documented fact that "Scoob" is a DINO (Dog In Name Only) he spends all his time with humans who keep him around only for the sake of saying they have a dog. He's clearly treated as lesser than his peers, with only shaggy making an attempt to understand dog culture. After 40-some years Shaggy is the only one even dares to try a Scooby Snack.
Marco-Doo is the only prominent Latin Republican in the Senate, with the notable exception of the scrappy Ted Cruz. He, like Scooby, refused to speak his native tongue. In fact, Rubio totally eschews his Hispanic heritage and culture only displaying it when he wants to bark at the cat of communism.
They both have brown hair
In Scooby's case it's more like fur I think but either way, brown.
They're both two-dimensional character's who simply go through the same steps over and over with no chance of growth
Whether it be the Gang of 8's attempt at immigration reform or his reading Jay-Z lyrics to help Rand Paul filibuster drone strikes, Rubio just goes through the motions. He makes some rousing speech or dramatic stand. Then he goes to a town hall and makes even bigger statements, all focused on an emotional level. Then he (if he's feeling like it) goes to the Hill and votes whichever way his friends are and nothing changes.
Scooby is a cartoon dog from a very formulaic 1960's children cartoon.