to allow their policies to be set by the 20% far left, they will never be in control of the government again.  They are still clinging to DEI when 70% of Democrats have rejected it.  Unless they completely shit-can everything they have been pushing the last four years and start with a clean slate the appeals to independents and moderate Dems, 2028 will be another Republican landslide.  Only 4% of independents think the Dems are on the right track.  

Times change. Parties change. I remember Progressives saying not that long ago that the outlook for the R party was bleak long term due to the "browning" of America i.e. more Black and Latino voters and an ever shrinking white majority.  
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You are also forgetting that Dems are making major gains in places like NC, GA, AZ and Texas. All four weren't even in play at all just 10-15 years ago, and were solid red, but the first three are now total toss ups and the gap in Texas has shrunk.