The first cardinal rule of politics is to focus on issues that unite your base and divide your opponents. For Democrats, those issues are the economy and abortion. For Republicans, that issue is immigration. The Republican base is united behind Trump’s draconian approach, but Democrats are divided on how to discuss the issue. That’s why conventional wisdom says that if this campaign is about immigration, Trump will win.

So, why did Kamala Harris take a day out of her busy schedule to head down to the border to give a speech about immigration and border security?

Over the last 24 hours, Democratic activists and Message Box readers worried that the Harris campaign was making a mistake or operating from a defensive crouch. I get that. It’s a close call, but I think her strategy makes sense. Here’s why:

1. Voters Care About Immigration

There’s this view that immigration fears in the electorate are borne of racist agitprop spewed by Donald Trump and Fox News. There’s some truth to that, for sure. The Right is always lying about what’s happening at the border, talking about “caravans” of MS-13 members making their way to your community, and hyping up any crime committed by an undocumented person (while ignoring the crimes committed by the Republican nominee). However, it’s condescending to suggest that the only reason voters care about immigration is because they had the wool pulled over their eyes. Some concerns are based on misinformation, but dismissing them outright is bad politics...