The House Majority PAC is spending $51 million on television ads in 29 markets to run in the final weeks of the 2020 election cycle, but not every vulnerable House Democrat’s district is covered.

According to the Democratic super PAC, the initial flight of ad reservations that the group is prioritizing are television markets that will be most inundated and expensive spots, due to the presidential election and competitive Senate races. By reserving ads now, the super PAC locks in the lowest ad rates as early as possible, as it preps television spots to defend the House majority Democrats won in 2018.