Democratic lawmakers started preparing for cyberattacks immediately following the 2016 election, warning that Russia would return, but the sense of urgency has grown in the past week as two senators confirmed hacking attempts.

Senate Democrats up for re-election in red states are the presumed top 2018 targets for Russia, which interfered in the 2016 election to boost then-candidate Donald Trump’s campaign. But Democrats running in pivotal House races are concerned they could be next, saying the attempted attack on Sen. Claire McCakill’s campaign is a fresh reminder.