On Immigration, Harris and Democrats Walk a Delicate — and Harder — Line

When Vice President Kamala Harris accepted the Democratic presidential nomination last week at her party’s convention in Chicago, she sought to strike a delicate balance on the issue of immigration, promising to approach enforcement and security at the nation’s southern border as the prosecutor she once was, without abandoning the country’s values.

“I know we can live up to our proud heritage as a nation of immigrants and reform our broken immigration system,” she said on Thursday night. “We can create an earned pathway to citizenship and secure our border.”

It was the kind of equilibrium on the issue that Democrats had striven for all week — a leveling between calls for more officers and judges at the country’s southern border and a system that treats people humanely, between promises to uphold the law and rebukes of the fear-mongering over “the other” that has permeated the national immigration debate.

But the overall message on immigration from the Democratic Party in the past week, as it has been since Ms. Harris announced her candidacy last month, has been decidedly more hard-line than it has been in decades. The shift reflects just how much of a political vulnerability the issue remains for Ms. Harris and down-ballot Democratic candidates in November, as many voters have come to see the challenges at the southern border as a top concern, and a small but growing minority of Republicans and independents want to curb pathways into the country.

The most common refrain from the stage in Chicago was a denunciation of former President Donald J. Trump and Republicans for tanking a bipartisan border security deal this year that, as former President Barack Obama said on Tuesday, was “written in part by one of the most