Editor's note: Julian E. Zelizer is a professor of history and public affairs at Princeton University's Woodrow Wilson School. His new book is "Arsenal of Democracy: The Politics of National Security: From World War II to the War on Terrorism," published by Basic Books. Zelizer writes widely about current events.
(CNN) -- Republicans and Democrats in Congress seem to have found one issue on which they agree. Neither party wants to get near immigration reform, the new "third rail" in American politics -- an issue so politically charged that politicians risk their careers by touching it.
Since Congress failed to reach agreement on legislation in 2006 that would have offered undocumented immigrants amnesty and a path toward naturalization, both parties have kept as far away from this issue as they did from health care after President Clinton's reform went down to defeat in 1994.
Last week, Senate Majority Leader Harry Reid, D-Nevada, announced that Democrats would tackle immigration reform, although he made some statements a few days later that seemed more hesitant. Despite Reid's promises that Democrats will deal with this issue, the verdict is still out as to how much political capital the party is willing to invest.
Although President Obama has repeatedly stated his support for immigration reform, there is still little evidence that the Democratic Party or the GOP is prepared to join colleagues like Sen. Charles Schumer, D-New York, and Sen. Lindsey Graham, R-South Carolina, to fight for legislation.
If Congress is unable to pass immigration reform, it will create more opportunities for states to move forward with the kind of harsh restrictionist measures passed by the Arizona Senate on Monday.
The failure of Congress to pass immigration reform has been a national travesty. Since Congress passed legislation in 1965 that opened the doors to millions of immigrants from Asia, Central and South America, the Caribbean and Mexico, the government has passed a series of bills establishing rules for newcomers.
In 1986, Congress passed legislation that enabled certain illegal immigrants who had been in the country since 1982 to submit an application for legalized status. Four years later, Congress increased the maximum number of immigrants who could enter the United States in a given year.
President George W. Bush's background in the multicultural state of Texas led him to champion the value of immigrants to the economy and culture of the United States. Politically, Bush and his advisers imagined that if Republicans could win the support of the Hispanic population, they could secure a huge and growing voting bloc that would strengthen the electoral standing of the party. Many Republicans, including business leaders who traditionally supported liberalized immigration laws, agreed on creating a hospitable environment for newcomers who were integral to the labor force.
Yet a hard-line anti-immigration faction in the GOP stifled efforts to pass legislation. In 2005, the House passed a stringent anti-immigrant bill that would allow illegal immigrants to be imprisoned. The response of the Hispanic community was to mobilize and launch a massive wave of social protest.
The Republican Senate responded by rejecting the House bill and instead passing legislation that strengthened border security at the same time that it created opportunities for undocumented immigrants to obtain citizenship.
Acknowledging the need to secure the borders, Bush told Americans that we "must honor the great American tradition of the melting pot, which has made us one nation out of many peoples. The success of our country depends upon helping newcomers assimilate into our society, and embrace our common identity as Americans."
Even though the Senate bill had President Bush's support, the legislation died by 2007. The failure to create opportunities for undocumented immigrants to obtain citizenship or to offer them worker protections ignores the crucial role that immigration has played and continues to play in this country.
We are a country of immigrants. We were immigrants from the start. Colonial and Early Republic America was itself composed of a diverse population whose members came from England, Scotland, Ireland, the Netherlands, Germany and more, as well as the people who were brought here as slaves from African nations.
From the 1840s through the 1890s, a huge wave of immigrants arrived in the wake of downward business cycles and famines in Eastern Europe, as well as persecution. About 15 million people entered the country from Germany, Ireland, Britain and Scandinavia.
Another wave of immigration hit between the 1890s and 1920s, with almost 18 million people arriving from Italy, Austria-Hungary and Russia. As President Lyndon Johnson said in 1965, when he signed immigration legislation of his own, "Our beautiful America was built by a nation of strangers. From a hundred different places or more they have poured forth into an empty land, joining and blending in one mighty and irresistible tide. The land flourished because it was fed from so many sources -- because it was nourished by so many cultures and traditions and peoples."
Both political parties have sizable factions who strongly support liberalizing and stabilizing the treatment of undocumented immigrants. Although both parties agree on the need to establish limitations on who and how many people can enter the country and to secure the borders, they also recognize that government must ensure opportunities for citizenship for those who have worked and spent dollars in our economy.
Yet the leaders in both parties have not had the courage to take action to make immigration reform a reality. Reid's quick reversal shows the kinds of fierce political pressures that exist.
But these fears cause the parties to miss a massive opportunity. Not only can the party that acts first fulfill a strong and long-standing tradition in American history, but it would also earn the loyalty of those families who gain citizenship. During the 1930s and 1940s, Eastern European immigrants became a bedrock to the New Deal coalition because Democrats had supported them.
President Obama has stated his support for liberalized immigration reform, but thus far his party has not taken action. We will have to see whether Obama is willing to demonstrate the same kind of political courage he did with health care, when he took on another issue that everyone thought to be a third rail in politics.
The opinions expressed in this commentary are solely those of Julian Zelizer.