House Democrats' main super PAC is winding down its spending in several races where the party has struggled to make headway despite national trends working in their favor .

Why it matters: Democrats' ambitions of winning heavily Republican districts are running into the reality of finite resources at the end of a long and expensive midterm campaign.

The Democratic Congressional Campaign Committee and its corresponding super PAC, House Majority PAC, have struggled to keep pace with their GOP counterparts' monster fundraising this cycle.

Republicans also have the bonus advantage of a network of cash-rich outside groups, namely President Trump's MAGA Inc. and Elon Musk's America PAC .

Driving the news: HMP pulled back its spending this week in three Republican-leaning districts, according to AdImpact and a source familiar with the matter.

TN-05: Democrats were bullish about their star recruit, Columbia Mayor Chaz Molder, until redistricting made the district redder and embattled Rep.…