While sharing anecdotes on bringingNissan's first manufacturing plant to Tennessee during his time as governor, U.S. Sen. Lamar Alexander outlined Thursday three keys for the state to maintain its position in automotive manufacturing.

Alexander, who was speaking at AutoConnect 2014, an auto industry conference hosted byFrost Brown Todd law firm at the Music City Center, first pointed to preserving Tennessee's right-to-work status.

"Defend the right-to-work law. That's important and it's under attack," Alexander said, adding that union actions before the National Labor Relations Board "can send a real chill to efforts to recruit a tier-two supplier to Tennessee.

"If a plant in Michigan, a supplier who wants to come to Tennessee and gets stopped by an action by the National Labor Relations Board, that might discourage that from happening," Alexander said. He pointed to a union attempt to prevent Boeing from moving part of its operations from Washington to South Carolina, which has a right-to-work law.

The attempt to unionize the Volkswagen plant in Chattanooga has been the most visible push against Tennessee's predominantly non-union automotive sector, with a potential impact for automakers throughout the Southeast, as the Nashville Business Journal reported last year.

In a February vote, workers voted not to affiliate with the UAW, though the union group has since started a voluntary campaign to sign up workers. Volkswagen has said it would recognize the union once it represented 50 percent of the plant's workers.

"Defending [right-to-work] in the future may be just as important to us as it was in the past in terms of attracting, not just Nissan and Volkswagen, but General Motors and the UAW partnership," Alexander said Thursday.

Alexander's second point: maintaining the state's highway infrastructure, which he said is crucial for suppliers getting their parts to factories and manufacturers delivering their products to dealerships.

Tennessee has been able to build its roads without accumulating any debt, which Alexander says "has been a tremendous advantage to our state."

Yet he adds, "There will come a time, in order to maintain our [highway] advantage, the state will need to pull out a road plan … they don't need to wait on the federal government for a solution."

And lastly, Alexander said, Tennessee needs to enhance its skilled-labor pool. Alexander, who is up for re-election to the U.S. Senate this November, applauded fellow Republican Gov. Bill Haslam's program to make two-year community and technical college free to the state's high-school graduates.

"These are highly skilled jobs that need more highly skilled people," Alexander said.