The permitting bill enters a critical stretch

Data: Columbia University Center on Global Energy Policy; Table: Ben Geman/Axios The push to pass a sweeping permitting bill is gaining powerful allies and encountering fresh resistance as Congress prepares for a post-midterms showdown.

Why it matters: It's the most important energy bill in a long time.

Cutting hurdles for projects is a top priority for fossil fuels and renewables sectors.

But some environmentalists say it badly weakens crucial protections in the name of speeding reviews.

Driving the news: A new, interactive analysis out on Wednesday projects potentially huge time savings if the bill becomes law.

Transmission projects could see the biggest acceleration, per Jack Andreasen Cavanaugh, a researcher with Columbia's energy think tank.

He based it on historical data about a large number of specific projects, then estimated how much quicker they would have proceeded under the bill.

Columbia's Center on Global Energy Policy doesn't have an institutional position on the bill.

But founding director Jason Bordoff, a prominent voice in energy policy circles, is urging environmentalists not to oppose it.

State of play: A who's who of economic and national security officials spanning six presidents (including Trump) are linking arms behind the bill in a new letter to Capitol Hill leaders.

What's next: The effort goes beyond signatures for some of the former officials, according to letter organizer Arnab Datta of the Institute for Progress, a nonpartisan think tank.

"Some folks are engaging beyond the letter itself with stakeholders across the board, and some have made themselves available for members briefings or conversations," he tells me via email.

Catch up quick: The letter from 19 officials includes Biden-era Treasury Secretary Janet Yellen and Trump 1.0 Treasury Secretary Steven Mnuchin, among five people who held the job.

The list also features Trump 1.0 Secretary of State and CIA boss Mike Pompeo, and Leon Panetta, who had top Obama-era defense and CIA gigs, to name just two others.