WASHINGTON — Italy may be the next stop on the world’s journey to more economic nationalism. First we had Brexit — Britain’s decision to leave the European Union. Then we had the election of Donald Trump as the next U.S. president, pledging to put “America first” in his policies. Now Italy may be treading down the same path.

What’s at issue is a constitutional referendum, scheduled for Dec. 4, that would make it easier for the parliament to pass measures intended to improve a lackluster economy. But the latest polls suggest the referendum will fail, placing Italy in a precarious economic and political position.

Almost everyone agrees that Italy’s economic performance needs help. According to figures from the Organization for Economic Cooperation and Development (OECD), growth of the economy (gross domestic product) has been limping along at less than 1 percent annually, while unemployment is about 11.5 percent. Government debt is 132 percent of GDP.

In an ideal world, faster economic growth would enable Italy to pay down its debt and reduce unemployment. But Italy’s political system is “gridlocked,” says Jacob Funk Kirkegaard of the Peterson Institute, a U.S. think tank.

It’s hard to loosen the economy’s shackles. The legislature has upper and lower houses that must pass identical bills; there is no reconciliation system of differences as exists in the U.S. Congress. Coalitions are often unwieldy because there’s no effective limit on small parties, and legislators often switch their allegiances.

The referendum would reduce these obstacles, says Kirkegaard. First, the powers of the upper chamber would be confined to local issues and its members would be appointed, not elected. Next, a party in the lower house that obtained 40 percent of the vote would automatically receive enough extra seats to give it a majority.

The idea is to centralize power, making it easier to streamline the economy. Presumably, if the referendum passes, Prime Minister Matteo Renzi would propose policies covering labor markets, taxes, regulations and government spending.

But if the referendum fails, the spillover effects for Italy and the rest of Europe could be nasty. Writing in The Hill, economist Desmond Lachman of the right-of-center American Enterprise Institute put it this way:

“Italy could be in for a prolonged period of political and economic uncertainty. Such an outcome could throw into question the country’s continued euro membership” — its use of the euro as money — “and could raise basic questions as to the eurozone’s chances for survival in its present form.”

A widely agreed vulnerability is Italy’s banking system, which is heavily invested in weak loans and Italian government debt. According to the OECD, about 18 percent of banks’ business loans are “non-performing,” meaning interest or principle aren’t being paid on time.

“If you have a crisis in the Italian banking sector,” said economist Megan Greene of Manulife Asset Management on CNBC, the business-news cable channel, “that could spread across Europe.” A banking crisis would probably involve panicky withdrawals from suspect banks. European officials have downplayed the danger.

If the referendum is rejected, some blame will likely be heaped on growing nationalism and distrust of distant bureaucracies — this time the headquarters of the European Union in Brussels, which has urged Italy to overhaul its economy. But there’s another factor as well: Renzi’s declaration that he would resign if the referendum failed. This is largely viewed as a blunder, says Kirkegaard, because it seemed arrogant and united many voters who dislike Renzi, for whatever reason.

The presumption is that after a failed referendum and a Renzi resignation, a temporary government would be appointed and a general election called. One winner is likely to be the Five Star Movement, an anti-establishment and environmental party that has been critical of the European Union.

Robert Samuelson is a columnist with The Washington Post.