The development of party political tactics really does depend on the Electoral College, a necessary evil and yet a problem.
Go back and look at the electoral map
from, say, 1940.
The media myth goes something like "the country was really liberal blah blah blah." Not "really" because the Democrats of 1940 (nationally) would never recognize the largely pacifist group running things now. (The Republican isolationists would recognize that particular segment of today's GOP, but still.....)
Look closely:
the South is SOLIDLY Democratic...FDR carried 95% of the vote in MS and 85% in AL, where blacks couldn't even vote.
The Republican wins Vermont - VERMONT - by nearly ten points and Maine as well.
And AZ and NM are Democratic.
Go to 1944 and you see - literally - the exact same outcome except three three states flip - WI and OH go Rep while MI goes Democrat.
(You can observe this same basic concept when the Republicans pretty much were assured the White House in almost every election from 1868-1932).
The Democrats had an Electoral College lock. And further proof comes in 1948, the infamous "Dewey Beats Truman" headline. Why did the Chicago paper think that? Well, Strom Thurmond ran as an avowed racist heading the States Rights party and Strom took 39 electoral votes that Truman would have gotten otherwise. Truman finished second in MS and LA despite his executive order ending segregation in the Armed Forces during the 1948 campaign. He wins those Southern states otherwise.
Now go look at 1952 - Eisenhower shatters the Solid South (so much for the revisionist myth of the so-called Southern strategy) by snagging Virginia and Tennessee while barely losing KY and SC. But look a little closer - the Rust Belt of the time from NY/NJ to Minnesota had 246 EVs, and if you count western Massachusetts at the time, you have 262 EVs when you only needed 266 to win.....and Texas was solid Democrat, too.
The Democrats literally had the election pretty much locked up before it ever got started (just as the GOP did for that 70 year span following the Civil War). It had NOTHING to do with 'liberalism' or 'battles of ideas,' it was a tactical battle to get 266 EVs. Back then we were a union heavy country in the Rust Belt and the South was still angry about Republicans over the Civil War.
Despite the carping, what happened was NOT the myth we're sold. Just go look at what happened with the EV totals, that's all you have to do, comparing the last dominant Democratic era (LBJ was an outlier in 64) and the end of the so-called Reagan realignment
STATES EV TOTALS 1948 (1988)
New York 47 (36)
PA 35 (25)
Florida 8 (21)
Texas 23 (29)
CA 25 (47)
So Truman wins three and gets 56 EVs while Dewey wins 82 because he carries his home state of NY by less than one point (the Dems win this if Dewey isn't the nominee) and PA.
In the forty years afterwards, families from the cold Rust Belt migrate to Texas, Florida, and California in search of both opportunity and warmer weather. So in 1988, Bush wins FOUR of those states and pockets 122 EVs while losing only 36. Consider this: Dukakis carried ten states and won 112 EVs (one faithless elector selected Bentsen as Prez fwiw); a Democrat carrying nine of the same states in 1948 (Hawaii was not yet in the Union) would have 126 EVs, and since HI is part of the Dem base let's give them those three.
1948: 129
1988: 112
17 electoral votes is HUGE in elections like 2000, 2004, and 2016. (OK, it's YUGE in the latter one). That's three of the last five elections and going back to 1960 we've had four total wipeouts, SIX close elections (60-68-76-00-04-16) and five 'could have gone either way' elections. And 92 could easily have gone the other way (a switch of 300,000 votes strategically in ten states re-elects Bush, which is why the Perot myth is not totally untrue.....just almost totally untrue).
What keeps the Democrats alive right now is the fact that several states like Illinois, California, Michigan, and New Jersey, all of which were Republican states for so long, are now solidly Democratic states.
From 1968-1988, it was not "racism" that won the White House for the GOP. Once again, just to look at the electoral vote. Nixon gets 40 for his home state of CA that Truman won in 48 but only got 25 votes. Nixon did NOT win because of "the racist Southern strategy" - he lost SIX of the 11 Southern states (not including Florida, which isn't considered Southern nor Texas, which Humphrey won). Wallace got 46 EVs; had he not been running, Humphrey gets AT LEAST 27 of those and probably 34 (Arkansas was virtually a tie between Nixon and H3 for second place).
Humphrey didn't lose because of a racist NIXON vote; one could argue he lost because of a racist Wallace vote, true. But then again.......go look at the reliable Democratic base in the Rust Belt. Nixon snagged NJ, OH, IN, IL, and WI from that area of the country. In 1960, JFK carried IL and NJ, which was 43 EVs that Humphrey lost in 68.....and he lost the election by 55 (you have to divide the total by two). If Hubert had carried the reliable Democratic base then he's within striking distance despite the Vietnam War and riots in the streets. (On another insane note - Humphrey did not run a single commercial in that campaign until October 24, for an election to be held on November 5 - this according to reporter Teddy White, who wrote the campaign book in early 1969).
Of course I've meandered but that's the point - part of the reason is TACTICS and strategy are what win the Presidential election, NOT really ideas. This explains quite easily how you can show me a poll where 58% of the public defines themselves as pro-choice and yet a hard-right pro-life candidate like Reagan can not only win, he can win a colossal landslide. Uh, two landslides.
Most discussion among the great washed about so-called election realignment is hogwash. It reaffirms their prejudices that left is good/right is evil (it's always amusing to me how many political scientists/reporters can actually SEE this when they're looking at the Religious Right's moral views on elections but don't realize it in their own stupid analyses; they're more fundamentalist than the fundamentalists).
States (for better or worse) have declared their allegiance to particular teams. Everyone knows right now today that in the 2020 election - even if the Democrats nominated Satan (like they did in 2016, ha ha) and the Republicans nominated Hitler/Stalin/Qaddafi/Hussein........the Republican is going to win both Kansas and Utah and the Democrat is going to win California without ever setting foot in the state except for fund-raisers. The battle is over states where both parties have a chance. Let's be honest: Hillary picked Tim Kaine for ONE reason and ONE reason only........he put Virginia in her hip pocket and its EVs. As much as I despise the woman, this was nothing new and happens virtually every election (Pence is the rare anomaly because he got chosen both as a sop to the social conservatives and because Kasich didn't want any part of Trump). Obama didn't pick Biden, though, for those three votes in Delaware, he picked him because Biden was not Hillary, had some stature, had good press relations, and was capable of acting like an adult (with occasional lapses that were hilarious). But note that the VP selection is almost always from a swing state:
2012 - Ryan (WI)
2008 - Palin (chosen because of women angry that Hillary lost and a mistake)
2004 - Edwards (put NC in play)
2000 - Cheney was actually chosen for the same reason as Biden
1996 - Kemp (NY)
1992 - Gore (chosen to show that Clinton was more of a Southern Democrat than a Northern liberal)
1988 - Bentsen (they hoped to win TX; they wanted Glenn, which is who the GOP feared would get it); Quayle was chosen, allegedly, because he schmoozed Bush's rear end all the time on Capitol Hill
1984 - Ferraro (NY), lost the state but it was more in play than it would have been
1980 - Bush (TX) - people forget TX was once a Democratic and then a swing state
The point is that the parties are into 'winning' and 'winning' requires winning tactics. If that screws the voters, to hell with them is the mantra backstage.