Editor's Note: (Julian Zelizer is a professor of history and public affairs at Princeton University and a New America fellow. He is the author of "Jimmy Carter" and "The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society." The opinions expressed in this commentary are his. )
(CNN) The political establishment has been sounding pretty sanctimonious these days. In both parties the leadership has railed against the insurgent campaigns -- Bernie Sanders and Donald Trump -- not only raising concerns about the candidates but also expressing dismissive sentiments about the voters who are supporting these campaigns.
Among Democrats, the party leadership has looked down on Sanders voters who it believes are unrealistic about their goals and falling for simplistic analysis about how politics works.
When one reporter said to former Congressman Barney Frank that it seemed he was saying Sanders voters "have a slightly unrealistic sense about the political process," Frank responded, "I didn't say slightly."
On the Republican side, many party leaders and prominent conservative pundits describe Trump supporters as working and middle class Americans being duped into following the xenophobic and angry rhetoric of the frontrunner.
But as voters go to the ballot box Tuesday in Wisconsin, it is a good time to take a closer look at what's been going on in the electorate. Though the terms usually used to characterize the voters who are shaking up the conventional wisdom are "angry" and "frustrated," there is much more going on. And much of it stems from the problems in the political system itself.
For many years commentators have been warning about the way the connections between money, lobbying, and politics have been damaging the body politic.
Many of the voters in both parties have a fairly clear-eyed understanding of some of the basic problems that are afflicting the nation's political process and, regardless of what one thinks of the candidates, those problems are pretty substantial.
Rather than simply think of ways to stifle these insurgencies, the parties should take a closer look at themselves and their approach to government.
Sanders has talked a great deal about the corrupting influence of money on politics. While some Democrats dismiss this as merely a one-issue candidacy focused on inequality, Sanders has insisted that this issue is so big it pervades almost all aspects of the political system. The power of money within the party system, he has argued, rigs the rules of the game so that the constituencies whom Democrats have claimed to be championing -- the middle class -- keep losing out.
Both parties have become too influenced by the world of lobbyists and campaign donors. Democrats, at a time that the party decided to focus more on appealing to suburban, professional voters, became more intertwined with the world of campaign contributors from the world of business, who are often less hospitable to policies that protect workers or help the disadvantaged.
Republicans, who were already starting from a position that social safety net programs are never a good thing, have moved even further away from middle- and working-class concerns as a result of the extremely tight alliance between wealthy donors and GOP officials.
Liberal Democrats have seen the consequences of these changes firsthand in Wisconsin, where Gov. Scott Walker, with the ongoing support of the Koch brothers, has conducted a systematic and vigorous campaign to undercut the power of unions in one of the most progressive states.
He has also gone after the state's prestigious university system, historically a hotbed of progressive thought. And although his presidential campaign failed, Walker has been extraordinarily effective in his own state. Supported by big donors, Walker was able to emerge as one of the most powerful voices in state politics and undercut the power of the public unions.
The Wisconsin chapter of Americans for Prosperity (the local affiliate of an organization founded by the Koch brothers) has poured resources into anti-union campaigns in the state.
The corporate-funded Club for Growth paid for ads against labor unions during Walker's battles. He relied on the Koch brothers to help him in the fight against the liberal backlash to his policies.
When he faced a recall election in 2012, Walker received substantial financial support from Americans for Prosperity.
As the power of the union movement diminished, the influence of Democrats waned.
Whereas 11.7% of the state's workforce belonged to unions in 2014, only 8.3% were members one year later as a result of numerous factors, including Walker's policies.
Walker has adopted policies that favor the energy industry, in which the Koch brothers have major interests, by moving to dismantle key environmental regulations.
While donors may be satisfied, the alliance between business and the Republican Party has led to policies that fundamentally disadvantage working-class Americans. Regressive tax policies, deregulation and diminished social services, all of which the GOP has gradually embraced, have left many Americans more vulnerable than ever before to the vagaries of the economy.
Though many economic indicators are better in Wisconsin than other parts of the country, a large number of voters are feeling the pain of losing strong unionized jobs that have been replaced by positions that are less secure and often don't cover the basic financial needs of their families.
While Republicans since Ronald Reagan have tried to win over Democrats by promising they can offer a better deal, in Wisconsin many have learned that this is not the case. The party often used social and cultural issues as a way to win over these voters despite the disconnect between the party's economic agenda and their pocketbook concerns.
A recent article in The New York Times by Nicholas Confessore recounted how the party became more closely allied to Wall Street at the expense of the growing number of blue-collar voters who were voting for the GOP. Confessore quotes a Republican public relations executive who worked for the Heritage Foundation in the 1980s and said: "Thirty years later, the same people are sitting in Washington that I worked with, making a million a year, going to fancy dinner parties, and they've done nothing to move the ball. Therein lies the great chasm between the think tanks, the ideologues and the real world."
So while Trump offers most of the wrong solutions, there are good reasons his appeal has hit home with many voters. It is unclear whether this will be enough to win the state. Recent polls show Ted Cruz doing extremely well, particularly after a series of controversies have raised yet more questions about the viability of Trump as a potential president.
Trump's recent comments about punishing women who received abortions, a remark he soon retracted, raised even more concerns from women voters about his policies and generally about how prepared he is on key issues.
Yet Trump still holds the delegate lead nationally, and it's clear that his campaign has resonated, in terms of its message, with a large number of voters.
Rather than focus only on the messenger, both parties would do well to listen to what the voters are saying and to become more introspective about what role they have played in generating so much unrest. Both Democrats and Republicans are not simply blindly rebelling this year, they are using their voices to address some big and basic problems in American politics that have been ignored for far too long.
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