I emotionally hopped on the Straight Talk Express in 1999, one of just a few of my GOP friends to do so. While the word “maverick” has tempered over the years as we’ve come to expect the unexpected from Sen. John McCain, at the time I was drawn to the freshness of his establishment-rousing talk and approach. One Saturday morning during primary season, I woke up early and did something I had never done before (and didn’t do again until 2016): I made a presidential campaign donation. I called McCain headquarters at a pre-sunrise hour and a real live person answered the phone. She sounded tired (or maybe I was projecting) and I recall as we chatted she mentioned not having had her hair cut or colored in months because all her free time was devoted to helping him win. I had called intending to donate $25 and instead gave $100, a huge amount for my Senate salary.

“Bless you,” she said. I joined as a campaign volunteer (how I wish I still had that McCain t-shirt) and worked the polls on primary day in Virginia. His loss devastated me. But then he got to remain in the Senate, where his environmental efforts seemed to crisscross mine.

Over my Senate career, two issues I worked on near and dear to my heart were Army Corps of Engineers reform and climate change. McCain championed both.

I look back on the 2003 vote on the McCain-Lieberman Climate Stewardship Act as a defining moment in my involvement with the issue. Working for The Nature Conservancy at the time, it was all hands on deck calling Senate offices. We didn’t have board approval to officially (i.e. publicly) endorse the bill, but off the record, we called our best contacts to say we quietly supported it. I reached out to the offices of Maine Senators Susan Collins and Olympia Snowe; New Hampshire’s Sen. Judd Gregg; and Indiana’s Sen. Richard Lugar. I’m not taking credit for how they voted as I’m sure McCain himself persuaded their position, but my “team” all voted yes. We still lost and the rest is history but to think that in 2003 we came five votes shy of the 60 needed in the complicated U.S. Senate astounds me today, when only three percent of Americans have faith Congress will act on climate change.

McCain was the godfather of the GOP climate movement and a guide to my former boss, Sen. John Warner, who embarked on his own climate bill with Sen. Joe Lieberman in 2007. While McCain was busy running for president (including on his climate record), Warner still had constant questions for him which I needed to answer.

“How did McCain address this in his bill?” Warner frequently asked.

“I think…”

“Stop thinking and start knowing.” Needless to say, I consulted frequently with McCain’s staff, always as responsive, informed, and thoughtful as their boss.

For the last 15 years or so working on climate change and as a citizen concerned about other pressing issues, I grew to expect McCain to be there, not always voting the way I wanted or agreeing with my personal position because our heroes don’t have to think and talk just like we do. But his passionate, determined, and fair approach to policymaking (and life) served as an example I try to follow. I’ve wavered between weeping and sobbing since the news of his passing; the world feels darker and scarier without his straight talk to guide us. There is no American who has given more in service to his country so it feels selfish to wish we could have kept him longer. I hope Americans of both parties will not just praise him in his death but take on the mantle he wore in life.