Percent of election issue tweets about immigration. (MIT Laboratory for Social Machines)

Immigration, a major topic throughout this presidential campaign, has dominated the election-related conversation on Twitter in the past week.

According to the Electome — a project of the Laboratory for Social Machines at the MIT Media Lab that’s been analyzing social media data about the election — since the beginning of August, tweets about immigration usually make up around 18 percent of the Twitter conversation around core election issues.

But tweets on immigration soared to almost 60 percent of the election-related Twitter conversation after Donald Trump’s statements about a potential “softening,” his visit to Mexico and then his address on the topic Wednesday night in Phoenix.

In the past two weeks, the Republican presidential nominee spurred much of the discussion around his stance on immigration. On Aug. 23, at a town hall telecast with Fox News’s Sean Hannity, Trump said that “there certainly can be a softening” on immigration. The next day, tweets on immigration made up 30 percent of the core election issues conversation on Twitter. That number went even higher Wednesday, when Trump met with Mexican President Enrique Peña Nieto and then gave an incendiary speech on immigration, hitting 40 percent. The day after his address, it made up 59 percent.

Clinton followers (Twitter users who follow Hillary Clinton and no other presidential candidate) seemed particularly eager to discuss the issue: Since Aug. 23, the immigration portion of their conversation leaped 14 percentage points over the August average, while for Trump followers it jumped only 9.5 percentage points.

The conversation around race has also picked up recently; usually tweets on racial issues make up 12 percent of the Twitter conversation about core election issues. Those tweets on core issues were drawn from more than 20 million election-related tweets in August.

Percent of racial issue tweets about immigration. (MIT Laboratory for Social Machines)

But on Aug. 25, the portion of tweets about racial issues grew to 26 percent, coinciding with Clinton’s speech tying Trump to the “alt right” — a conservative movement often associated with white nationalism.

(MIT Laboratory for Social Machines)

It’s difficult to disentangle race and immigration issues, but as of Friday afternoon, the percentage of tweets about race started down toward their early August levels, even as the portion of tweets on immigration continued to grow.