Though Democrats are poised to make significant gains in the House next month, thanks to a Senate map that’s put them on the defensive in disproportionately red states, Republicans are still odds on favorites to maintain control of the upper chamber. Should they come up short this time, it may be natural to look toward 2020, when they hope an unpopular incumbent President Trump could weigh down Republicans, and bring Democrats unified control of Washington. While this is of course possible, it’s worth noting that the 2020 Senate map is not particularly easy for Democrats, either.

On paper, the next round of Senate elections promises to be much easier than 2018. While Democrats have to defend 26 seats in 2018 compared to just 9 for Republicans, in 2020, it’s Republicans who have to defend 22 seats compared to just 12 for Democrats. The difference is that this year, Democrats have to defend a number of Senate seats in hostile territory, such as North Dakota, Indiana, and Missouri, whereas in 2020, Republicans are on relatively safer ground.