With less than a month to go until November's midterm elections, the battles for both chambers of Congress are diverging.

Republicans' hold on their Senate majority appears to have tightened in the wake of Supreme Court Justice Brett Kavanaugh's confirmation, but Democrats are favorites to seize control of the House as more key GOP-held seats tilt away from Republicans, according to top election forecasters.

Recent developments have only strengthened this year's prevailing narrative: that Democrats will likely struggle to navigate the Senate even as party enthusiasm helps them unseat vulnerable House Republicans across the country. Split partisan control of Congress appears to be the most likely scenario when the new session starts in January.

Democrats need to flip 23 GOP-held districts to take control of the House. If Republicans can stop Democrats from taking two Senate seats — a manageable task as Democrats and independents who caucus with them defend 26 seats — they will hold their Senate majority.

Of course, much can change in 3½ weeks, but here is how top forecasters viewed the midterm battlefield as of Thursday afternoon: