At a breakfast in Washington on Thursday, Sen. Bernie Sanders (I-Vt.) dismissed any perception that he's radically outside the American mainstream. Referring to his core campaign positions, he said: "It is not a radical agenda. In virtually every instance, what I'm saying is supported by a significant majority of the American people."

That's a claim worth double-checking. We pulled the key components of his announcement speech and looked at the most recent polling on each to see just how much support Sanders's proposals had. It doesn't take very long before we get mired in the ways polling can fail to capture the nuance of the issue but, spoiler alert: Sanders was generally right.

His positions and the polling on them are below. All positions are quoted verbatim from his Web site.

Jobs, Jobs, Jobs: At a time when our roads, bridges, water systems, rail and airports are decaying, the most effective way to rapidly create meaningful jobs is to rebuild our crumbling infrastructure. That’s why I’ve introduced legislation which would invest $1 trillion over 5 years to modernize our country’s physical infrastructure.

A Fox News poll from earlier this year would suggest that Americans aren't as enthusiastic about this plan as Sanders thinks. A large majority oppose spending on infrastructure ... if their taxes go up.

Which, of course, is a giant caveat. Last November, a poll without that qualification showed that Americans "strongly" or "mildly" support infrastructure spending by a wide margin.

Verdict: America agrees with Sanders, if it doesn't cost them more.

[Trade:] For decades, presidents from both parties have supported trade agreements which have cost us millions of decent paying jobs as corporate America shuts down plants here and moves to low-wage countries.

This one is a gimme -- much to President Obama's chagrin at the moment.

Verdict: Americans agree with Sanders.

Raising Wages: The current federal minimum wage of $7.25 an hour is a starvation wage and must be raised. The minimum wage must become a living wage – which means raising it to $15 an hour over the next few years – which is exactly what Los Angeles recently did – and I applaud them for doing that.

Americans generally support raising the minimum wage.

There's been some polling on raising it to $15, the focus of an organizing effort around low-wage workers, but over time, as Sanders proposes.

Verdict: Americans agree with Sanders.

Addressing Wealth and Income Inequality: [W]e need a tax system which is fair and progressive, which makes wealthy individuals and profitable corporations begin to pay their fair share of taxes.

Another gimme.

Verdict: Americans agree with Sanders.

Reforming Wall Street: It is time to break up the largest financial institutions in the country.

There's not good, recent polling data on this rather esoteric question. A 2009 Bloomberg poll had 10 percent support for breaking up large banks -- but 31 percent for letting them fail and 52 percent for greater regulation. That said, people don't trust banks, so it's likely they won't be too aggressive in coming to their defense.

Verdict: Undetermined.

Campaign Finance Reform: [W]e must be deadly serious about campaign finance reform and the need for a constitutional amendment to overturn Citizens United. ... Long term, we need to go further and establish public funding of elections.

There hasn't been as much polling on this issue as you might assume. Earlier this month, a CBS News-New York Times poll asked about money as free speech, with people generally taking the anti-Citizens United position.

Public funding of elections was polled by Gallup in 2013. At that point, a flat 50 percent said they'd vote for public funding, were it on the ballot.

Verdict: Americans agree with Sanders.

Reversing Climate Change: Millions of homes and buildings need to be weatherized, our transportation system needs to be energy efficient, and we need a tax on carbon to accelerate the transition away from fossil fuel.

Climate change is also tricky. People are asked how important it is to them when voting (usually not very) and if they feel as though it is a real phenomenon (usually they do).

The most contentious of the proposals above is the idea of a tax on carbon -- that is, taxes that are linked to the amount of the greenhouse gas carbon dioxide that are emitted from a source. In 2014, Yale and George Mason asked about that, including an estimate of cost.

Without that estimate, a survey from January fielded by SRSS on behalf of Stanford, the Times and Resources for the Future found a majority of Americans backed "requir[ing] companies to pay a tax to the government for every ton of greenhouse gases the companies put out." A version of the question that added, "All this tax money would be given to all Americans equally by reducing the amount of income taxes they pay," did even better. Unsurprisingly.

Verdict: Undetermined.

Health Care for All: The United States must join the rest of the industrialized world and guarantee health care to all as a right by moving toward a Medicare-for-All single-payer system.

This one is straightforward.

Verdict: Americans don't agree with Sanders.

Protecting Our Most Vulnerable: Instead of cutting Social Security, we’re going to expand Social Security benefits. Instead of cutting Head Start and child care, we are going to move to a universal pre-K system for all the children of this country.

A 2013 survey from AARP found that 69 percent of Americans opposed the idea of reducing the annual increases to Social Security, but that's not what Sanders is saying here. A Pew poll from the same year found that 41 percent of Americans wanted to increase spending on Social Security, while 46 percent wanted to keep it the same and 10 percent wanted to decrease it. As with other things, this question is tightly linked to what the benefits are and what the costs are, and there doesn't appear to be good polling to that end.

The other proposal is easier.

Verdict: Mixed.

College for All: I will fight to make tuition in public colleges and universities free, as well as substantially lower interest rates on student loans.

When the president proposed making community college free, reaction was not overwhelmingly positive. Sanders's proposal goes further.

The closest we can get to the interest rate question appears to be from a poll last November -- but it's a doozy.

Verdict: Americans generally agree with Sanders.

War and Peace: We must be vigorous in combatting terrorism and defeating ISIS, but we should not have to bear that burden alone. We must be part of an international coalition, led by Muslim nations, that can not only defeat ISIS but begin the process of creating conditions for a lasting peace.

Interestingly but not unexpectedly, Sanders's discussion of foreign policy is relatively light. How do you judge that?

Verdict: ?

The overall verdict? Yes, Americans broadly support the things that are on Sanders's agenda, with a number of particular footnotes.

We have to note, though, that there's a contingency that isn't mentioned: The ability of Sanders -- or anyone -- to make these things happen on Capitol Hill demands far less optimism.

Sen. Bernie Sanders (I-Vt.), a White House contender in 2016, is known for his stances on budget issues and war. Here are his takes on Obamacare, Social Security and more. (Julie Percha/The Washington Post)