Rep. Timothy Johnson wants voters in Illinois’ new 13th district to know that he walks the walk and talks the talk — and that should not be difficult. If there are two things the Republican is known for, they are walking and talking.

But the six-term Republican is adding a layer of difficulty to the already arduous ritual he takes of telephoning each one of his constituents: keeping in touch with his current 15th district while introducing himself to a brand-new swath of voters in the new district he will run in next year.

The practice comes with operational challenges as well. House rules forbid the use of official resources for campaign-related activity, so he uses one phone to call constituents and another, paid for by campaign funds, to call would-be constituents.

A staffer said he stashes another five or six phones in various places around the Hill because his batteries frequently run dry.

“I’m not trying to pose as holier than Caesar’s wife, but I do try to go out of my way [to] do everything ethically and aboveboard,” Johnson said.

Johnson spends nearly every waking minute between votes, meetings and committee hearings ambling the halls of the Longworth House Office Building’s fourth floor or circling a nearby park, cold-calling constituents.

“I don’t like to let grass grow under my feet,” he said on a recent afternoon, cellphone to his ear, promenading around a park outside the Rayburn House Office Building. “If there’s an hour of otherwise dead time, I’m going to use it either in the office or out around the area, calling constituents and asking what I can do to serve them better.”

Because of redistricting, however, Johnson is losing most of the people he has called over the years. The new district in which he plans to run includes just 30 percent of his old terrain.

But as the new Illinois map awaits a court challenge, Johnson is walking full speed ahead toward a new constituency, courting potential voters with his quirky take on representative democracy.

“Calls like this, while they’re not political, the net result is that if you talk to Mr. and Mrs. Jones in Cerro Gordo, Ill.,” he explained, “and they said, ‘Here’s what the problem is,’ and I solve the problem, there’s a pretty good likelihood that they’re going to vote for me.”

His office estimates that he walks some 20 miles per day — part of a monastic health habit that includes near-constant exercise and limiting his food intake. Meanwhile, he calls up to 200 constituents, phone numbers gleaned from countless call sheets his staff prepares for him.

He has perfected his routine to a science, greeting constituents with an affable banter that manages to sound at once formulaic and unscripted.

“Ms. Cloverline?” he asked, on a typical call to a woman in Monticello, Ill., in his current district. “Oh, hi, Ms. Cloverline. This is Tim Johnson calling you, Congressman Tim Johnson, how are you?”

A short pause.

“You’re going to have to remind me … Oh sure, absolutely! So Marguerite is Lynn’s mother right? … Oh yeah, and your sister lives in Philo? … Well I’ll be darned, small world isn’t it?”

When asked after hanging up if he had phoned an acquaintance, he smiled slyly and replied, “Well, she knew me.”

Interactions like this are not uncommon for the rail-thin 65-year-old Congressman, who estimates he has dialed more than a half-million constituents over his 12 years in office and thousands more during his two decades in the Illinois state Legislature.

A poll commissioned by his office years ago found that 52 percent of his constituents think they know him personally.

That is about to change.

Redistricting has dramatically reshaped his district, drawing the region away from Eastern Illinois so that it juts southwest nearly to St. Louis.

The changed demographics are expected to give Johnson his first competitive election since he entered Congress. And for the first time in years, voters do not know his name.

Greene County State’s Attorney Matt Goetten, who initially declined to run, changed his mind this week and will seek the Democratic nomination for the seat, setting up a primary with David Gill. The general election is expected to be competitive.

As a result, Johnson has added a new element to his calling ritual: He has slowed calls to constituents he will no longer represent and has taken to calling areas that will be part of the new district, hoping an onslaught of calls will prevent the phones from going dark permanently.

A typical call will now go something like this:

“Hi, Ms. Jackson? My name is Tim Johnson, Timothy Johnson. It’s kind of an unusual call, but I’m not soliciting anything,” he said, calling a woman in a small southwestern Illinois town. “I’m the United States Congressman, Mrs. Jackson, for Champaign-Urbana and Decatur, but because the Legislature has recently changed the lines, real quickly here, I am going to be hopefully representing Jerseyville. So I just wanted to call and say hello to you and let you know who I am one-on-one, rather than through those answering devices or prerecorded phone calls.

“I’m hitting my stride,” Johnson said with a touch of irony after the call. “Name recognition is the name of the game. In areas that are quite a bit removed, many people don’t know who I am, so part of what I have to do is introduce myself.”

He laments, he said, having to leave behind so many people he has represented for more than a decade but said he is ready for a campaign.

“It’s challenging, and it’s invigorating,” he said. “In some ways, it’s like you graduated from the law school of government and politics and then all of a sudden you’re back in undergrad.”

His hallmark as a legislator is that he has helped adjudicate everything from veterans assistance claims to cockroach infestations for his constituents. In the new district, he is restricted from solving problems for those who are not yet his constituents. But for now, he said, he refers the problems to the relevant agency or Congressman.

“After a year, when I’m elected, I’m going to extend that specific service to people in the new district,” he said.