In Pennsylvania, four congressional districts exemplify the types of seats that Democrats are aiming to flip. Our national political correspondent Shane Goldmacher explains.

Many election officials fear that the Trump administration is laying the groundwork to challenge the midterm results in November if they do not favor Republicans. Our White House correspondent Zolan Kanno-Youngs describes what the administration is doing.

The Supreme Court is starting its new term already mired in election disputes. Our reporter Ann E. Marimow explains why the court is likely to get pulled into even more of these cases.