I think you’re over complicating things here.
2007-2008: Vitter has a scandal with escorts. It's bad, it alienates large swaths of of the population.
2010: Since Louisiana is a conservative place and 2010 is a historically good year for Republicans, voters overlook his scandals and he wins 57 percent of the vote to be re-elected Senate.
In his time as a senator he campaigns bigly against Obamacare. This is a long-term blunder as large constituencies in his state support Obamacare and will greatly benefit from Medicaid expansion. This will hurt him bigly in the next state-wide election because...
2015: He wins the GOP nomination because of his conservative views. However, because of his scandals and position against Obamacare and Medicaid expansion (popular among even repubs) it dooms him against a conservative Democrat who doesn’t have scandals and who supports Medicaid expansion, investing in public education, etc.
2019: Despite Louisiana still being fairly conservative, they re-elect their Democratic Governor because of his strong support for public education, Medicaid expansion, and balancing the budget. As many of us pointed out at the time Obamcare was being debated, it would end up being popular even in red states as large groups of the population would benefit by it. Even a strong effort by the president couldn’t push the republican candidate over the finish line in a republican state.
Why this matters?
- First, it shows that Trump isn't a magician. His unpopularity among key groups of people have doomed the candidates he's endorsed. Had Trump built bridges with people of color and suburban women, Democrats wouldn't be having near the success that they're having nationwide. Which is something to consider if you're a Republican Senator, no matter what type of state you're in. No Senate seat is safe.
- Secondly, it shows that local politics still matter. The people of Louisiana, while still being quite conservative, do however care about things that matter to them, like Medicaid expansion, public education support, balancing the budget (not giving away handouts to rich people), and not having scandals (remember, Democrats hold theirs accountable far more than Repubs).
- Lastly, attempts by Trump to nationalize local elections are failing. He wanted Louisianians to forget about Edwards' efforts to improve public education and expand Medicaid and give him (Trump) a win. He's tried this several times now, and he's lost.
this article explains some things pretty well. 2010 was an outlier election too, as that was Obama’s first midterms and it was historically good for Repubs. (not sure why it became underlined)
https://www.washingtonpost.com/news...ion-problem-kill-him-in-2015-and-not-in-2010/