2018 midterm elections

Which parties control each state legislature and governorship

Data: National Conference of State Legislatures; Note: Nebraska’s legislature is non-partisan and D.C. does not have a governor; Chart: Harry Stevens/Axios

Heading into 2020, Republicans hold 27 governors' mansions while Democrats have 23. The GOP controls 30 state legislatures to Democrats' 19. Nebraska has a unicameral, non-partisan legislature.

Why it matters: Where the country heads on a number of key issues including abortion, gerrymandering, Medicaid, minimum wage, paid family leave, criminal justice and infrastructure is determined by action at the state level.

The Democratic hunt for a 2020 down-ballot message

Across all congressional races in the 2018 midterms, health care was overwhelmingly the top issue that Democrats referenced in their digital and TV advertising, according to data from Advertising Analytics, a firm that specializes in media ad spending and real time political ad detection.

Reproduced from Advertising Analytics; Chart: Axios Visuals

Why it matters: In addition to knocking off an incumbent in the White House, Democrats are facing an uphill battle to win the Senate and a very real possibility of losing their House majority. While several themes are emerging for what could be key themes of the party's 2020 platform, candidates have yet to rally around a single down-ballot issue that could turn voters out in droves like health care did in 2020.