The real root of the distrust here goes back to the botched 840 planning. The state spent tens of millions of dollars, maybe even hundreds of millions, that could have gone toward matching the federal share on other projects (I-69, TN 385, I-475, US 27, etc.) to avoid doing a federal EIS on 840 (and dug in their heels under West Tennessee governors like Sundquist and McWherter, I might add), and then the state dragged the construction out so long that the EIS and inevitable lawsuits really wouldn't have delayed its completion much.
I think politically the winds aren't right at the moment, but eventually the Democrats will figure out again how to run statewide candidates in the south who can go back to the Whitten/Byrd days of "tax the rich yankees and spend it here in the south," or the southern GOP will figure out how to run on that platform again instead of the zealously-anti-(non-military)-pork one. That's the politics that built roads like I-68, I-22, and the original I-49, for better or for worse. But I wouldn't count on the rump Tennessee Democrats like Kyle to make that happen; Memphis is basically at the bottom of the state GOP's Christmas Card list, after decades of Democrats running roughshod at the state level, and it's gonna be a while before the GOP is done returning he favor.