Sen. Angus King’s political career has truly come full circle.

Jan. 3, 2013, the day he was sworn in for his first term as Maine’s junior senator, marked 40 years to the day that he got his start on the Hill as a legislative assistant to then-Sen. William Hathaway, D-Maine, a role he’d serve in for two and a half years before heading back to his home state to start his own law practice.

King is just one of a whopping 73 members who worked as a staffer on Capitol Hill before being elected to Congress — a list that includes 13 senators and a host of House members who have served anywhere from one term to several.

Other staffers-turned-members include: Senate Minority Leader Mitch McConnell, R-Ky., who worked both as an intern and later a full-time staffer for two Kentucky senators; former Republican vice presidential nominee and current House Budget Chairman Paul D. Ryan, R-Wis., who interned for Wisconsin GOP Sen. Bob Kasten; and Democratic Congressional Campaign Committee Chairman Steve Israel, D-N.Y., who worked as an aide for two members of Congress while attending George Washington University. Not on the list but equally as interesting is Senate Majority Leader Harry Reid, D-Nev., who worked on the Capitol Police force to help pay the bills while attending George Washington University Law School.

King, 69, said the experience working on Capitol Hill not only taught him how the place works but also helped him craft a leadership style for those who now work for him in a staffer capacity.

“I’ll never forget, I was having lunch with some staffers for another senator, this was 40 years ago, and I happened to mention my boss, Bill Hathaway, was interested in this and this and this,” King said. “And the other guy asked me how I knew, and I said because [Hathaway] told me.  . . .  Then I asked him, ‘How do you know what your senator wants?’ and he told me, ‘We read tea leaves.’

“I never want to be a senator where my staff needs to read tea leaves to figure out what the hell I want to do,” King said.

To ensure his staff knows what he’s thinking, King said he spends a lot of time calling meetings to update them on what he has been working on, and he often brings younger staffers, such as legislative correspondents, to committee hearings and markups to give them a taste of how the Hill hums.

“When I was [on the Hill], I remember the staff was sort of isolated, and I remember thinking that we’re all working away here but we really don’t see our senator very much, and we really don’t have a greater sense of what’s going on,” King said. “I said [to myself], ‘I’m not going to be that way.’”

King added that he came into his role as a legislator with managed expectations for what could be achieved as a senator, and he said he’s been focusing on the ways he can have an effect on the ongoing debate on the Hill in a meaningful way in his first few months on the job.

“[Working on the Hill] was an important part of my experience because I did come in with some knowledge of how the place works, and  . . .  a realistic perspective,” King said. “I didn’t come in totally naive, expecting to change the world.”

Rep. Luke Messer, R-Ind., the freshman Republican class president, also got his start on Capitol Hill as a legislative assistant in the 1990s for Rep. John J. Duncan Jr., R-Tenn.

Messer — who also worked for former Reps. Ed Bryant, R-Tenn., and Indiana Republicans David McIntosh and Dan Burton — said his time on Capitol Hill was instrumental to helping him adjust to life as a member.

Key leaders of Messer’s staff, including his chief of staff and legislative director, are people Messer met while playing softball during his summers in Washington, D.C.

And he added that he’s adopted certain leadership traits from each of the members he worked with.

“I probably borrowed a little bit from each of them,” Messer said. “Jimmy was always very focused on constituent services and understood that to be a member of Congress, you have to keep folks at home happy. So we run a Jimmy Duncan-like constituent services program.”

From Bryant, Messer said he learned to trust and empower staff by giving them a lot of responsibility, and from McIntosh, Messer learned the importance of being a substantive legislator.

“[McIntosh] was somebody that in his six years out here was active in trying to pass bills, and [my staff and I] were able  . . .  to pass a bill in our first 50 days,” Messer said. “So I learned from David that the best way to legislate is to start legislating.”

For staffers looking to parlay their Hill experience into becoming a member one day, King said not to stay on the Hill for longer than three or four years.

“Nobody gets elected to the Senate from Washington, D.C.,” King said.

“I also left because I found myself laughing too loudly at my boss’s jokes,” King added. “Working in the Senate is like being a lawyer with only one client. When you’re not serving them with your best advice and counsel, it’s time to move on.”

Messer used UCLA Hall of Fame basketball coach John Wooden’s famous quote “Inch by inch, life’s a cinch. Yard by yard, life is hard” to suggest that staffers looking to become members should take things one step at a time.

“My biggest advice is to focus on doing your current job well and try to avoid thoughts of some long-term, grand plan,” Messer said. “If you do your current job well, there’s a pretty good chance you’ll continue to get further and further.”