The big-spending Republican groups focused on keeping the House are moving large sums into some unexpected districts in an effort to shore up seats and incumbents that looked safe for their party until just a few weeks ago.

The National Republican Congressional Committee made a last-minute $800,000 buy to back up Rep. Jaime Herrera Beutler (R-WA) in a GOP-leaning seat on Thursday, while the Congressional Leadership Fund, the GOP’s main House super PAC, launched $500,000 worth of ads to try to save an open seat that runs from Tampa to Orlando, according to sources tracking the buys.

Strategists on both sides had viewed both seats as leaning towards the GOP heading into October, but Democrats have grown especially bullish about the open Florida seat, where public and private polling have recently found a tied race. Herrera Beutler has looked a bit safer, but the GOP wouldn’t be dropping badly needed resources on her behalf if the race looked like a lock.

The new ad salvos with less than two weeks until election day are the latest moves by the pair of GOP groups to shore up seats they hadn’t been worried about heading into the campaign’s home stretch — and a sign that the combination of a big Democratic candidate money advantage and high levels of Democratic enthusiasm is leaving the GOP scrambling to plug holes in the congressional map in their uphill battle to hold the House.

And they’re not the only recent major investments from GOP groups in recent days. The NRCC also recently dropped $1.4 million to shore up Rep. Karen Handel (R-GA), who famously won a hard-fought special election in early 2017 and had been viewed as fairly safe since then, and $600,000 apiece for Reps. Brian Mast (R-FL) and Ted Budd (R-NC). The CLF is now spending for Reps. Fred Upton (R-NY) and John Katko (R-NY) as well as to hold an open seat in Virginia, while a Trump-aligned super PAC has gone in big to shore up recently elected Rep. Troy Balderson (R-OH), who is being badly outspent by Democrat Danny O’Connor, who Balderson barely beat in August.

This last-minute backstopping on these districts comes as Democrats have held a massive candidate spending edge in many of these races. Democrats are outspending Republicans by a combined $155 million to $83 million right now, a 2-to-1 margin that’s hard for outside groups to make up for since candidates get much cheaper advertising rates than party committees and super PACs.

Katko’s, Budd’s and the open Florida seat appear to be the most vulnerable of the bunch.

Most if not all of these seats still lean Republican, however, and much of this money appears to be coming in to match Democratic groups who’ve gone on the air in these districts in order to avoid a nasty surprise for the party rather than because of outright GOP panic about any of the races. The open Florida seat, for instance, has seen a combined $1.7 million spent on advertising from the Democratic candidate and the Democratic Congressional Campaign Committee to just $200,000 from the Republican candidate.

But the House map does seem to be moving into redder territory in the race’s closing days, a good sign for Democrats as they look to net the 23 seats needed for a majority.

This story was updated at 2:55 p.m.