Pierre Stephen Fowler

Last year, a handful of Republican Indiana state lawmakers blocked a push to redraw the state's congressional boundaries.

A slate of Trump-backed challengers pushed out five of the seven incumbents targeted in the primaries.

Another race is currently separated by just three votes.

In Ohio, there weren't competitive primary contests for governor or U.S.

Senate, but both are expected to be expensive and contested in November's general election.

One reason?

Trump's rising unpopularity.

Another is Democratic enthusiasm, where every state that's held a primary so far this year has seen a surge of Democratic turnout compared to prior midterms.

Stephen Fowler, NPR News.