“Let me tell you now about the single biggest lie in politics: It is that Republicans are the party of the rich. What complete nonsense. Do you know that under President Obama, the top one percent, those millionaires and billionaires that the president loves to demagogue, the top one percent are currently earning the highest percentage of our national income since 1928? Listen, when the government expands its control of the economy, the rich do fine. Five years ago if you had a private jet you’re still flying the private jet. Who are the losers? Who are the people who are getting hammered by the Obama economy? It’s the most vulnerable among us.”

— Sen. Ted Cruz, R-Texas, speech in Iowa, Oct. 26, 2013

This may seem like an old quote, but it’s a regular part of Cruz’s stump speech to declare that the “single biggest lie in politics” is that Republicans “are the party of the rich.”

We stumbled across this interesting observation just this week when Alex Moe of NBC News tweeted about Cruz’s March 18 speech in Mason City, Iowa.

We could not find a clip of that speech, but we found three other versions of the same talking point, including an extended discussion on Reason TV in January.

Here at The Fact Checker, we don’t like to use the word “lie” – it seems rather pejorative – but a politician describing something as the “biggest lie” is irresistible. What’s the basis for this claim?

If you listen to Cruz, he never really explains why he believes this is the “biggest lie.” Instead, he attacks President Barack Obama for presiding over an increase in income inequality and says that the president’s policies, such as the health-care law, have negatively affected “young people, Hispanics, African Americans, single moms.”

In the Reason interview, Cruz said:

“I try to look at every policy issue from the perspective of my dad in 1957 washing dishes, making 50 cents an hour. If my dad were washing dishes today, the odds are very, very high he would have lost his job because of the crushing taxes and regulations that are hammering small business. Two-thirds of all new jobs come from small businesses.

“If my dad hadn’t lost his job, the odds are overwhelming he would have had his hours forcibly reduced to 28 or 29 hours a week because the threshold for Obamacare is 30 hours a week. And, he wouldn’t have been able to pay his way through the University of Texas at 29 hours a week. He wouldn’t have been able to feed his kid at 29 hours a week. And if he doesn’t have that first job washing dishes, he doesn’t get his second job working as a cook. Which means he doesn’t get his third job as a teaching assistant, which means he doesn’t get his fourth job as a computer programmer at IBM.

“We need to be focusing on how policies impact those who are struggling and every policy we think about and talk about should make it easier for those who are struggling to climb up the economic ladder and achieve the American Dream.

“One specific point that Cruz makes is that the Dodd-Frank banking law, which he asserts had the “intended consequence” of making big banks bigger and small banks disappear because only larger banks could deal with the law’s regulations. Cruz appears to associate big banks with the wealthy.”

In essence, Cruz suggests that Republicans focus more on the needs of small businesses, which in turn lift up the poor.

“It’s a response to a common claim by liberals that Republicans only care about defending the wealthy,” Cruz spokeswoman Catherine Frazier said. “The senator’s point is that the core of Republican principles are not about propping up the wealthy, but about helping the little guy – not through a government handout, but through empowering those with less to climb up the economic ladder one rung at a time – that is accomplished by scaling back big government, keeping power with local and state governments so that the private sector can thrive.”

But what does the data show? Cruz said “of the rich,” which certainly suggests voting patterns. A 2013-14 Washington Post-ABC poll show wealthy Americans are not universally Republican, though they tend to lean and vote that way.

While Cruz says the image of Republicans as the party of the rich is a Democratic lie, it is also widely believed by Americans. The 2012 exit poll found 53 percent said GOP nominee Mitt Romney’s policies generally favored the rich, 34 percent the middle class and 2 percent the poor; for Obama, just 10 percent thought his policies favored rich, 44 percent the middle class and 31 percent the poor.

A CNN/ORC International poll, conducted Jan. 31-Feb. 2, asked: Do you think the policies of the Democratic/Republican party generally favor the rich, favor the middle class, or favor the poor? Here are results:

Favor rich: Democrats: 30 percent; Republicans: 69 percent

Middle class: Democrats: 36; Republicans: 23

Poor: Democrats: 30; Republicans: 3

No opinion: Democrats: 3; Republicans: 4

Finally, since Cruz is arguing that Republican policies are better for the poor and Democratic policies tilt toward the rich, we sought out the source of his statistic about the top 1 percent earning the highest percentage of our national income since 1928 – Emmanuel Saez, a professor at the University of California at Berkeley.

“Overall, if you look at the full century of evidence, the rich do better under Republicans (or least Republicans put in place deregulation+less progressive taxation that allow the rich to thrive later on),” Saez said in an email. “That said, there are exceptions. Since 2009, the recovery has been skewed dramatically toward the rich. Obama’s policies most likely to affect the income gap (higher taxes on the rich, financial regulations, Obamacare) don’t kick in till 2013 or 2014 so you can’t blame those here.”

Saez suggested we contact professor Larry M. Bartels, of Vanderbilt University, who he said has done the most comprehensive examination of the issue.

“I think the data support the view that Republican presidents have tended to do much better (with respect to income growth) for affluent families than for middle-class or (especially) poor families,” he said. The wealthy tend to do well under either party, whereas the poor and middle class appear to do better under Democrats.

Frazier argued that we are looking at this wrong:

— “This is not about who votes for who — it’s an argument that Republican policies can help those with less more than Democrat policies.”

— “We aren’t about public opinion polls, but making an argument that individuals are empowered to thrive more under Republican policies than Democrat policies.”

— “This isn’t about rich faring better under Republicans or Democrats — the rich fare better when government is big. We argue that the poor have a better chance of succeeding under Republican policies of smaller government.”

But, as always, the burden is on the person making the claim. One could have the opinion that Republican policies will be better for the poor, and obviously Cruz believes that.

But, without more evidence, Cruz simply can’t pair it with a sweeping statement that saying Republicans are the party of the rich is “the biggest lie” when decades of economic data show the poor do better under Democrats, that the rich tend to vote Republican and that most Americans believe Republican policies favor the rich. We note that he never makes an affirmative case for why Republicans are not the party of the rich; he simply knocks Democrats.

Indeed, it’s appears likely that Cruz’s “biggest lie in politics” is actually the truth.

Read The Fact Checker: the Truth Behind the Rhetoric, at www.washingtonpost.com/blogs/fact-checker