Democrats believe the outcome of the Louisiana 5th district special election indicates Sen. Mary LandrieuMary LandrieuFive reasons the Trump campaign is in deep trouble Louisiana gov: Trump helped 'shine a spotlight' on flood recovery Giuliani: Trump 'more presidential' than Obama in Louisiana visit MORE (D) can use ObamaCare as an advantage in her reelection fight.
"His overwhelming victory supports what polls have indicated for months: voters don't want to repeal Obamacare, like Sen. Mary Landrieu they want to fix it so that it works for as many Louisianians as possible, and they support expanding insurance through Medicaid at virtually no cost to taxpayers," Zucker writes.
McAllister's 20-point win over state Sen. Neil Riser was a surprise to political observers, as Riser had establishment backing and raised and spent considerably more money than McAllister.
But the eventual winner, a first-time candidate and businessman, emphasized his outsider credentials and sought to draw centrist and Democratic voters, which can vote in Louisiana's open primaries, with his embrace of the Medicaid expansion.
Democrats believe his win in the special is an indication that the Medicaid expansion is could be a winning issue in Louisiana's Senate race, as a Pew poll out earlier this year showed 63 percent of Louisianans viewing the expansion favorably.
Louisiana Gov. Bobby Jindal (R) turned down the expansion in his state, and Rep. Bill Cassidy (R), the establishment pick to challenge Landrieu, is an outspoken opponent of the provision. He has said it puts too much of a burden on states' budgets and doesn't address the issues with access to services that are already problems with the program.
He has, however, proposed legislation that would change the way Medicaid is financed that he believes would encourage more Republican governors to sign up for the expansion of the program offered under ObamaCare.
Zucker said in the memo that his opposition to the expansion "reinforces his growing reputation as a politician who can't be trusted to fight for Louisiana."
"Cassidy isn't just opposed to expanding Medicaid today; he's vehemently against it. As other Republicans are breaking party lines to expand Medicaid for tens of thousands of their constituents, Bill Cassidy is putting politics first and opposing expanding insurance for Louisianans without offering any sort of solution beyond boilerplate talking points," Zucker said.