Republicans are dramatically outspending Democrats on impeachment-related ads on Facebook and television, illustrating how fully the GOP has embraced the issue as a political winner as public opinion remains split on the House effort to remove the president.

The ad blitz has worried some Democrats in swing districts who are being painted as do-nothing, pro-impeachment radicals. The Democrats have been urging party leaders for weeks to strike back with their own counter-message, to no avail.

Over the past month, GOP candidates have used anti-impeachment messages to try to recruit new supporters, and independent big-money groups boosting Republicans have launched roughly $10 million in ads aimed at Democrats in districts that President Trump won in 2016.

Some of those vulnerable Democrats, who spoke on the condition of anonymity to talk candidly about private conversations, said party leaders told them the cavalry is coming but shared no firm date.