The article identifies ten closely watched US House and Senate contests that could determine which party controls Congress after November’s midterm elections.

– The Senate races are presented as pivotal to control of the upper chamber.
– Competitive House seats could decide the House majority.
– Outcomes may shape the next Congress’s legislative agenda and oversight powers.
– Both Republicans and Democrats are concentrating resources on closely divided districts and states.
– Narrow margins mean a small number of contests could prove decisive.