It is impossible to appreciate the scale of the federal budget. You know that numbers go million, billion, trillion -- one, two, three -- and probably that the budget's somewhere in the trillions.

But those numbers skip over the scale. A million is a lot of money, as you would probably agree. If a million is the one blue dot at right, a billion is a thousand of those dots. That chunk is one thousand million. When you get to a trillion, that's a thousand billion. What's shown in the graphic is not actually a trillion: it is five of the one thousand chunks of billions that would make up a trillion. It is to a trillion what those five lighter-colored circles are to a billion.

According to the White House Office of Management and Budget, you'd need 3,688 of those chunks of billions. Each dot of which is a million dollars.

It's hard to appreciate. Which is important context for considering a discussion that came up during Thursday night's debate.

Donald Trump was asked by CNN's Dana Bash how he'd address Social Security spending. Trump replied that he wouldn't touch Social Security, and instead would "get rid of waste, fraud and abuse."

Bash challenged that. "You're talking about waste, fraud and abuse," she said, "but an independent bipartisan organization, the Committee For a Responsible Federal Budget, says improper payments like you're talking about -- that would only save about $3 billion, but it would take $150 billion to make Social Security solvent. So how would you find that other $147 million?"

Trump's response? Get international partners to pay for the United States deploying its military. Negotiate better deals. Bring wealth back to the country.

Bash asked Rubio to chime in.

"The bottom line is, we can't just continue to tip-toe around this and throw out things like I'm going to get at fraud and abuse," Rubio said. "Let's get rid of fraud, let's get rid of abuse, let's be more careful about how we spend foreign aid. But you still have hundreds of billions of dollars of deficit that you're going to have to make up."

Trump rebutted once again. "I've been going over budgets and looking at budgets," he said. "We don't bid things out. We don't bid out, as an example, the drug industry, pharmaceutical industry. They don't go out to bid. They just pay almost as if you walk into a drug store. That's what they're paying."

So let's look at this. Here are the 2015 budget outlays.

Now let's add in the amount that Bash suggested would be cut by eliminating waste, etc.

There is a line there. It's just hard to see. That's the scale problem.

So what Marco Rubio is saying is that Trump's solutions don't come close to covering the numbers that comprise the federal budget. That's broadly true. You likely can't get that $147 billion Bash referred to by charging other countries to send troops for the same reason that Trump's proposed tariff against China would change the economy: People would stop paying.

But here's the thing: It's easy to see why Trump's rhetoric works. Why can't we just renegotiate where we're paying too much? Why can't we improve the economy enough that we're generating revenue to meet our needs? That's what we did in the 1990s, after all, and we briefly eliminated the annual deficit on the strength of our economic growth. Why can't that happen?

Those are the two fundamental theories in conflict during this Republican primary season. Rubio's is pragmatic, recognizing the scale at play, familiar with the paths that have been tried. Trump's is gauzier but more optimistic. It's fixable. We'll improve the economy. We can fix this. The inability to grasp that scale plays to his advantage directly.

That's the choice for Republican voters. Should we count all of those dots in that first graph, or should we trust that we can tackle however many dots we need to? That there's a way we can do better?

The latter idea, for a variety of reasons, is winning.