He's so well-known in the capital that he's frequently stopped on the street, whether by someone just saying hello or someone offering political concerns to the longtime Democratic senator.
Astle hopes to keep doing the people's work for at least four more years. Standing in his way is Republican Don Quinn, a political newcomer who is young enough to be Astle's son.
As Astle works to remind voters of his experience and connections at the State House, Quinn is offering himself as a fresh new face.
"John's looking backwards: 'I've done, I've accomplished, I've been,'" said Quinn, 34. "He's been there so long."
Astle, 71, says his experience is an asset, not a detriment. The retired Marine combat helicopter pilot likens choosing a candidate to peering into the cockpit when getting on a plane. "You like to see a little white hair up there because that guy knows what he's doing," he said.
Both men stray from their respective parties' typical talking points as they make their pitches to voters in District 30, which includes the Annapolis area and parts of southern Anne Arundel County. Democrats hold a registration edge, 55 percent to 45 percent.
Astle, for instance, has sometimes parted with Democratic leaders, voting against an increase in the gas tax and against stricter gun controls.
He enjoys telling a story from 2012, when he voted against an amendment backed by Senate President Thomas V. Mike Miller during a special session on gambling. Miller used profanity in scolding Astle over the phone in the Senate chamber — words that were inadvertently picked up by a microphone and broadcast online.
Astle says he has more work to do in the Senate, where much of his focus is on his adopted hometown of Annapolis. He points to his experience in helping constituents and business owners cut through government red tape. He's drawing up a bill to make it easier for city officials to deal with abandoned properties.
Quinn, meanwhile, says he would bring new ideas to the Senate. He says he wants to bring fresh eyes to state taxes and spending, toughen penalties for human trafficking and make it legal for small investors to buy shares of companies through crowd-funding programs.
"I would come in as the pesky newcomer. I'm not a politician," he said.
He doesn't echo a common Republican call to repeal stormwater management fees designed to pay for projects to reduce Chesapeake Bay pollution. Quinn says he doesn't like the fees — dubbed the "rain tax" — as enacted, but says it would be more productive to focus on creating a "lockbox" for the money and making sure it's spent effectively.
He's been questioned about his roots in the community. Quinn said he moved to the Annapolis area three years ago, first living in Arnold and then moving to the Hillsmere neighborhood of Annapolis last year. He registered to vote at his current address in January.
Quinn was born in Louisiana but spent most of his childhood in India before moving to Washington when his mother remarried in 1999. After the Sept. 11 terrorist attacks, Quinn joined the Army and served as a chaplain's assistant.
After leaving the military, Quinn worked a series of jobs before going into business for himself.
Quinn acknowledges that he has an uphill battle to unseat a well-known incumbent who is much better financed. Astle has nearly $200,000 in the bank and a long list of generous donors from past campaigns, while Quinn has less than $1,000 on hand, according to the latest campaign finance reports.
Astle says he isn't taking anything for granted and knows he has to campaign hard, especially in areas added in the last round of redistricting.
"I have to get to the people in south county who don't know me," he said.
Job: Five-term state senator; retired Marine Corps helicopter pilot and retired private medical pilot.
Family: Married, two grown children.
Job: Owns online marketing company.
Family: Married, five children.