I lived in KY for 5 years recently (2015-2019) after having previously there for two (2008-10). The state is more religious than most. It is more blue collar than most. It is more rural than most. It is more pro-gun and anti-abortion than most. As the parties picked sides on these issues and given that the national Democratic Party was of opposite opinions from these churchgoing, gun-toting rural folks on most of those issues, it became more difficult for Democrats to win in Kentucky.
The substantial change (in my opinion) came when Democrats for POTUS largely stopped competing there. I think Barack Obama and Joe Biden came once or twice each time they ran. Hillary Clinton and Tim Kaine never came and, of course, there was the whole issue with Hillary vowing to kill coal.
I lived big city (Lexington) the first time and in a small rural town the second. The town I lived in had almost every office filled by Republicans who ran unopposed in 2016 and 2018. Seriously, the town council had 9 member and there were 15 candidates running in 2018, all Republicans. The 2016 election flipped both houses of the legislature red for the first time in nearly 100 years. The current governor (took office last month) is a Democrat as was the one before Matt Bevin’s single term. Democrats CAN compete in KY, but they need to be different Democrats than the kind who compete on the coasts. Sort of like how Doug Jones could win in Alabama but AOC would not.
There is a similar issue in West Virginia. Donald Trump won there by 40+points. Democrats have largely written the state off, yet Democrat Joe Manchin keeps getting re-elected to the Senate. Sure, he is barely a Democrat at this point, but even that is better than a Republican, as they would run the most hardcore candidate they can find. I know the Democratic nominee for POTUS will likely see the allocation of resources to these states as a waste, but they must spend money and they must show up to campaign. Mitch McConnell is up for re-election in KY. Senator Shelley Moore Capito in WV is up for re-election. There are dozens of (maybe hundreds) of down ballot races in those two states. If the POTUS candidate does not fight for those states, both might turn red enough to have 2/3 majorities in the legislature. Since KY has a Democratic governor, that could lead to veto overrides and effectively make having won the governor’s race in 2019 pointless.
Lastly, it is damn difficult to win a Congressional race or United States Senate race without the party having a foundation. There must be a bench built. A person starts as a council member in a small town like the one I lived in. Then, maybe moves on to the state legislature and then maybe a statewide role like Agriculture Commissioner or Secretary of State. Finally, after 10-15 years, maybe a race for Congress or the Senate. But if every local office is held by Republicans, and they gradually keep taking a greater share of the statewide offices, it makes any Democrat wanting to challenge for high office usually someone with no prior elected experience or someone who does not have a lifetime of roots in the community.
The scary thing is, it took roughly 30 years for things to get so bad, dating back to when the most religious voters in KY and similar places started turning away from Democrats over Bill Clinton’s sexual proclivities. That cannot be undone in one or two election cycles. Same with WV. The Senate races might be different in an off year. That is how Doug Jones won Alabama and how Kentucky elected their current Democratic governor. Mitch McConnell is one of the must unpopular Senators in America. Amy McGrath (assuming she is the Democratic nominee) is a strong challenger. But as I noted when discussing what kind of candidates the party gets without a bench, she comes from the northernmost part of KY (just across from Cincinnati) and has never held political office (she ran for Congress in 2018).
I think on the question of how one man could amass so much power, the simple answer is that Mitch took steps no one else would dare take. There was a code in the Senate, some honor, a century of civility and polite, proper discourse. The House was the playground for children. The Senate was the private club for grownups. What happened in the Senate was the equivalent of gerrymandering the House, only it happened organically as population shifted to the coasts and as Democrats stopped competing in places like the South and the non-coastal West. Republicans knew when they too the Senate (and Mitch capitalized on this) that it would likely be a decade before Democrats would have ANY chance of taking the Senate back. It became a policy to obstruct everything when Democrats controlled the House or White House and to execute EVERY item on the Republican wish list if full control is achieved.
My grand-niece, when she was a toddler, used to be so very polite when she did not want to do something her mom told her. She would say, “How about…no?” It was cute from her, but when Mitch McConnell acts like a toddler, I do not get the same feelings.
Even now, polls say Democrats likely take Colorado and lose Alabama, leaving the Senate the same 53-47 it is now. Sure, A Democrat could win Maine, maybe Iowa too. That gets them to 51-49. Then what? What other seat could they take to get to 50-50 so a Democratic VP could break the tie? But there are more complications. Remember what I said about Joe Manchin? If the Senate is 50-50 and he is offered a leadership role (maybe even Majority Leader) to switch parties, might he? Think about it, would Republicans rather have a guy like Manchin as Majority Leader of have the Senate be in Democratic control? Also, if Warren or Sanders wins the White House (or if either is VP for a winning POTUS), the governor of their state would get to name a replacement. Both governors are Republicans. Would a Republican governor appoint a Democrat to fill the seat if that seat determined the majority in the Senate? Especially if Democrats hold the House? Basically, a Republican governor could have the power to decide if Democrats will have the sort of absolute control Democrats enjoyed early in Obama’s first term and Republicans enjoyed early in Trump’s. Seems every time I look up, Democrats need ANOTHER seat to take the majority.
A man like Mitch McConnell exists because he knows demographics have effectively gerrymandered the Senate and that Republicans HAVE gerrymandered the House and many state legislatures. McConnell and Senate Republicans have little to no fear of losing the Senate and know that if they hold enough state legislatures after the 2020 election they might be able to gerrymander their way back to House control even if they can not do it by winning elections.