Immigration has been a big issue in the presidential campaign. So have income inequality and gun control. But starting now — and perhaps continuing at length — political experts expect the race to focus on terrorism and foreign policy.

President Obama’s historic visit to Cuba, the highly scripted comments from Donald Trump to a Jewish lobby group, and the terrorist attacks in Brussels all occurring within days have set up a shift that could last until the general election, they say. This would be a dramatic change. Exit polls from the recent Illinois primary, for instance, found that the economy, income inequality, and government spending were more important factors to voters than terrorism.

“From Brussels to Braintree, the issue that very likely could drive the political conversation for some time is terrorism and national security,’’ said Robert L. Pfaltzgraff, a professor at the Tufts University Fletcher School of Law and Diplomacy and president of the Institute for Foreign Policy Analysis. “And you will find that candidates will seamlessly argue that domestic issues like border security and trade policy are international in scope.’’

Yes, this has happened before. In the aftermath of the Paris shooting attacks, voters told pollsters for the first time that national security and terrorism displaced jobs and the economy as the biggest issues facing the country. Within a month, the conversation returned to more domestic issues.

But the Brussels attack has occurred at the very moment when the front-runners for each party’s nomination are trying to pivot to the general election and show their foreign policy chops. Indeed, nonstop talk of terrorism in the news in the past week could be that last bit of help to Republican Trump and Democrat Hillary Clinton as they seek to clinch their nominations, according to Jennifer Merolla, a professor at the University of California at Riverside.

Merolla is coauthor of “Democracy at Risk: How Terrorist Threats Affect the Public,’’ which found that when there is a terrorist attack, voters look to strong figures — in particular Republicans, incumbents, and men — and are more distrusting of others, particularly immigrants.

“They suggest that some of the policies being advanced by the Republican candidates in reaction to Brussels would have support among the public, especially the Republican primary electorate,’’ Merolla said of her academic findings. “Since voters look for strong, charismatic leaders when terrorism is in the news, Republican primary voters may be more drawn to Donald Trump’s more aggressive and assertive leadership style. He did get a boost in support following the terrorist attacks in the fall. On the Democratic side, Hillary Clinton may be more advantaged with foreign policy becoming more salient given her experience as secretary of state.’’

David Paleologos, director of the Suffolk University Political Research Center, said he agreed that a campaign framed around terrorism could help Republicans win the White House.

“In the 2014 midterm elections, Republican candidates for Congress benefited from this issue because young parents, especially women, put the safety of their children before anything else,’’ Paleologos said. “Hillary Clinton cannot afford to give away any demographic of women, because she trails badly among men, especially white men.’’

Still, some like Providence College political science professor Joe Cammarano are skeptical that Clinton, with her deep experience in foreign policy, would lose out to Trump, who just announced his foreign policy team this week.

Cammarano, who has researched the shift in issue discussion in each of the past four presidential elections, believes the Brussels attacks will not change messaging in this campaign much beyond the next two weeks.

“If, however, additional attacks occur that are seen as similar to Brussels elsewhere, terrorism will return to front and center, and will shift candidate messages for a longer period of time,’’ Cammarano said.

James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell or subscribe to his daily e-mail update on the 2016 campaign at www.bostonglobe.com/groundgame