Things got tense for Democrats in the House this week. Lucky for us, our crack congressional correspondent Julie Hirschfeld Davis is here to explain:

Start with a fractious caucus of House Democrats that includes brash progressives clamoring for change and pragmatic moderates looking for compromise. Add months of simmering tensions over the Green New Deal, impeachment and defunding immigration enforcement. Sprinkle in a dollop of social-media-fueled sniping and a dash of racial resentment.

It all adds up to a feud, between Speaker Nancy Pelosi and four freshman congresswomen collectively known as The Squad, that doesn’t seem to be going away anytime soon.

Ms. Pelosi tried again on Thursday to shut down chatter about the increasingly public tensions between her and the group, telling reporters that she had “said what I’m going to say” on the matter to her caucus behind closed doors on Wednesday.

But the buzz continued apace, after Representative Alexandria Ocasio-Cortez of New York, one of the four freshman, suggested in comments to The Washington Post that Ms. Pelosi had repeatedly disrespected her and her colleagues because they were women of color.

Ms. Ocasio-Cortez told CNN on Thursday that she did not believe Ms. Pelosi was a racist, but the remark had already touched a nerve with the centrist Blue Dog Coalition, which dispatched a Democratic aide to suggest that it was the New York congresswoman who was responsible for injecting race into the conversation, when her chief of staff wrote a tweet last month comparing the Blue Dogs and other moderates to the segregationist Southern Democrats of the 1940s.

The feud is bigger than Ms. Pelosi and Ms. Ocasio-Cortez, and it has implications far beyond either of them. It points to the differences within the Democratic Party — demographic, generational and ideological — that are driving the crowded presidential race and the debate over how best to confront President Trump.

And the tensions are all but certain to flare anew in the weeks to come, as House Democrats complete a defense policy bill generating opposition from progressives, a $15-an-hour minimum wage bill drawing concerns from moderates, and legislation to set spending levels and raise the debt limit — all while continuing to grapple with whether to impeach the president.