The blue dogs were a rebranding of the already then existing conservative democrat. They were the democrats who represented much of the south, and were a major part of what formerly made the democrat party the big tent party, the fact they used to represent a large part of the country.
The blue dog coalition died under obama, not sure why they died but I can guess the dnc killed it off by trying to fund and push for social justice causes and candidates over the existing blue dogs, combined with republicans taking over those districts as those districts did not become less conservative, and if their favorite democrat conservative could not cut it, a republican conservative filled his place. Keep in mind though for blue dogs to return and thrive, the democrat party would have to abandon social justice causes as it's major platform and return to being the big tent party.
But if they were to do that, how could they claim themselves as liberals or being of the left?
I mean the establishment is already essentially right of centre (or just right if you use the rest of the developed world as a political barometer) 90s Republicans on economic matters. Without social justice issues to shore up their creds, they would literally be Republican lite in every respect.
So her strategy wasn't wrong, she simply underestimated the ignorance in this country--and instead of outing the unrealistic campaign promises of Sanders & Trump, she let it go--assuming Americans were smarter than that.
1930's--until the late 70's Democrats owned both houses of congress--and they were blue Dog Democrats. They appealed to the majority in this country which is why they won elections.
Again, on what planet is FDR a blue dog Democrat? There is nothing remotely blue dog about a man who defied the establishment and defied special interests and big money to author and enact the New Deal, and was consequently so popular that term limits were introduced to American democracy by angry and butthurt Republicans such as a very upset Thomas Dewey, still salty and outraged that he lost to the legend who went on to enjoy a fourth term until forcibly and unfortunately retired by cerebral hemorrhage.
Not even JFK in spite of his tax cuts, despite some identifying him as the 'first New Democrat', can be definitively called as much because taxes at the time were still high as a residual consequence of WW2.
As to Clinton's strategy, losing the rust belt or 'blue wall' says it all really. The woman flew over key states she should have campaigned hard in, and coasted on an almost unbroken narrative of how bad Trump was instead of talking about what she planned on doing for the working and middle class. On the flipside, you're at least not blaming Bernie supporters who turned out in support of her in greater percentages than Hillary supporters who voted Obama, so that's a start I guess.
FDR was not, is not, and never will be a BernieBrat ...
FDR was a populist who ran on a campaign of dramatic change and substantive reform in favour of constituents and in opposition to monied interests, and unlike Obama, actually enacted it.
Of all the presidents he's easily the closest thing to Bernie on the Dem side, and is absolutely not and in no way a New or Blue Dog Democrat; he is the diametric opposite to the bought and paid for corporatist Dems that now inhabit Washington today who disgrace his memory and make him turn in his grave. The man was Bernie before Bernie was Bernie.