Pete Buttigieg is out on the campaign trail, testing out a message that could take him all the way to the White House. The out former Transportation Secretary has yet to announce his widely anticipated 2028 presidential run — during an August interview, he said he’s “more inclined than not” to run again — and will not be on the ballot in Michigan this year, where he opted to sit out both the Senate and gubernatorial races. But with the 2026 midt…