It’s Monday evening, C-SPAN cameras are rolling and United States Senators are fulminating. A controversial measure to let states collect sales taxes from Internet retailers is coming to a procedural vote, over the objection of powerful committee leaders, one of whom is complaining about his own Democratic Party leadership “ramming this thing through.”

When Georgia Republican Johnny Isakson strides to the floor, it’s not for a speech. It’s for a deal. He huddles with a Democratic committee chairman, and they agree on what Isakson later calls “a pretty significant directional change” he would not detail.

“While all that rancor was going on, we were doing something that was going to make a significant difference and got it done,” Isakson told the Atlanta Journal-Constitution. “Those are the things you don’t see. Most of the stuff you see on the screen – with exceptions – is for the purpose of being seen on the screen, not for the purpose of getting whatever you’re talking about done.”

Getting it done matters to him. From building Northside Realty into a Cobb County powerhouse to a four-decade political career that has landed him as Georgia Republicans’ elder statesman, Isakson is all about the deal.

In the Capitol he’s known in both parties as a “gentleman” who is easy to work with at a time when distrust runs high and the Senate’s default state is Spaghetti Junction-level gridlock.

Many of Isakson's colleagues are bailing out, including his delegation mate and buddy of a half-century Saxby Chambliss, who will not run for re-election next year. But Isakson, 68, says he is running again in 2016, and by his personal charm and political instincts he has managed to duck many of the punches that have landed on Chambliss over the years.

The coming months will test Isakson's popularity at home and his dealmaking instincts in Washington. He will be targeted as a swing vote on a landmark immigration overhaul and any possible deal on the country's fiscal future. President Barack Obama asked him to organize a recent White House dinner with GOP senators where the budget was the primary topic.

Some in Georgia's conservative base don't like the notion of being represented by the man declared the "nicest" U.S. Senator in a Washingtonian Magazine poll of staffers last year.

“They come from a different era before the tea party, when everybody got along and they supported leadership,” Debbie Dooley, co-founder of the Atlanta Tea Party, said of Isakson and Chambliss. “But now times have changed and people want somebody who will stand and fight for their principles … They want a Navy SEAL representing them; they don’t want Barney Fife.”

***

Isakson has an easy retort for Republicans who complain about their 45-55 minority in the Senate: Try 24-156, the deficit Republicans faced in the Georgia state House when Isakson arrived in 1977.

As minority leader Isakson found a way to still get things done when, as he put it, “they can crush you like an ant.” He said he did not seek credit for some accomplishments, while sometimes exploiting divisions across the aisle.

As his clout rose Isakson sought higher office and was humbled twice, in a run for governor in 1990 and a 1996 U.S. Senate primary. In the Senate race Isakson’s pro-choice position on abortion helped sink him and he was tagged as too moderate to win a Republican primary.

Isakson had decided not to run for office again when Gov. Zell Miller, who beat Isakson in 1990, called with a proposition. Miller had fired the state board of education and wanted Isakson to take over.

“There’s some kind of trick in here somewhere,” Isakson thought, but he accepted.

The post kept him in the public eye, and when House Speaker Newt Gingrich resigned after Republicans lost ground in the 1998 midterms, Isakson jumped the next morning into the race to replace him. All of a sudden, he was in Congress.

In 2004 he survived a tough primary for an open Senate seat, with Rep. Mac Collins and businessman Herman Cain splitting the vote to Isakson’s right. Abortion was an issue again, though Isakson had shifted his position, saying he supported legal abortion only in cases of rape, incest and to save the mother’s life.

In the Senate, National Right to Life has given Isakson a perfect voting score. Yet anti-abortion activists in Georgia, who recall his votes in the U.S. House to allow personally funded abortions on overseas military bases, eye him warily.

“Honestly, he hasn’t sought out an endorsement, so that really is pretty telling,” said Melanie Crozier, PAC director for Georgia Right to Life. She said the issue will be a primary race vulnerability if Isakson runs again in 2016.

Other groups’ scorecards – closely watched by activists – place Isakson in the middle of the Senate GOP caucus, slightly less conservative than average.

“There are a lot of conservatives who look at his voting record and say this is not a conservative Republican from Georgia,” said Dan Holler, spokesman for Heritage Action for America, a wing of the Heritage Foundation think tank.

A recently released bipartisan Senate proposal to provide a lengthy, difficult path to citizenship for millions of people living in the U.S. illegally already is riling up the right. Isakson voted against a similar bill in 2007 after substantial backlash at home. He said last week something needs to be done on immigration and he looks forward to the debate.

Kay Godwin, of Georgia Conservatives in Action, who is staunchly against the immigration bill, wishes for a bit more clarity. “There are people that you don’t have to stand over their shoulder 24 hours a day to make sure they do the right thing,” she said. “We feel the pressure to put pressure (on Isakson) all the time on every big issue.”

But in many ways Isakson has avoided the heat that was focused on Chambliss before he decided not to run again. “That’s probably one reason he hates to see me go,” Chambliss said with a chuckle, though he added both of them get substantial grief.

To Virginia Galloway, Georgia state director of Americans for Prosperity, the difference between the two is Chambliss’ prominence in working with Democrats in the “Gang of Six” that considered tax increases as part of a deficit-reduction plan that never materialized.

“We don’t normally see Johnny in that role, as the public face that is reaching friendly across the aisle and trying to work on some kind of compromise,” Galloway said.

Others say Isakson’s advantage is his availability to all comers and easy embrace of hand-to-hand politicking. Even those who vehemently disagree with him praise Isakson personally.

“I don’t know of one person that does not like Johnny Isakson that has had a dialogue with him at any point in time,” Dooley said.

The same goes for Democratic opponents.

“He’s learned how to marshal and store political capital,” said Michael Thurmond, who lost a general election to Isakson in 2010 and calls him a friend. “It’s not party-specific capital. It’s human capital.”

***

He does it in a thousand small ways.

The day before Obama’s second inauguration, Isakson put out a food spread and spent hours shaking hands and posing for photos with Obama fans as they picked up tickets at his office.

For Obama’s State of the Union address this year, he invited Atlanta City Council President Ceasar Mitchell, a Democrat, to watch in person. It didn’t stop Isakson from bashing Obama right after the speech for “failing to lead,” but it was a meaningful gesture to Mitchell.

“I’ve had conversations with a lot of Democrats who in very quiet rooms will tell you, ‘I secretly voted for Johnny Isakson,’ people that you might be surprised to know,” Mitchell said.

Mitchell added that he had never voted for Isakson himself, but he admires the senator, is frequently in touch with him and considers him a great friend to the city.

Democratic and Republican senators said Isakson transcends regional and ideological cliques. Isakson’s salesman-like motto is “there are friends and there are future friends.”

In the 2009 stimulus law Isakson worked to insert a homebuyers’ tax credit, even though he did not vote for the bill. In 2010 he helped move the new START nuclear arms treaty through by winning commitments from the administration on modernizing the nuclear arsenal, Sen. Bob Corker, R-Tenn., recalled. He recently collaborated with New Hampshire Democrat Jeanne Shaheen to push the notion of budgeting in a two-year cycle, and the idea is gaining momentum.

Rarely does Isakson make a floor speech or stage a news conference. His highest committee post, vice chairman of the Ethics Committee, consists almost entirely of work done in secret.

In 2011 when an ethics investigation forced Nevada Republican John Ensign’s departure from the Senate it created an opening on the coveted Finance Committee. Isakson declined to go for it, lest anyone think the investigation was partly a tool to further his career.

“I begged him to take it,” said Orrin Hatch of Utah, the Finance Committee’s top Republican. “It just shows what a tremendously honest and decent man he is, because anybody else would have killed to get on the Finance Committee.”

This year Isakson finally secured a spot on Finance, where he will help shape discussions on remaking the tax code.

Chambliss’ January announcement that he would not seek re-election fanned speculation that Isakson would follow the same path in 2016. Isakson had a health scare in 2010 when he spent time in the intensive care unit with a staph infection, but it only briefly slowed him on the campaign trail.

He maintains he is in fine shape, and he’s “got my stickers already printed” for 2016, though it is a long way off and nearly all of the senators who recently announced their retirements, including Chambliss, insisted they were running until the day they weren’t.

Departing senators often cite frustration with inaction on big issues like budget deficits and the endless partisan brawling. Isakson said he continues to find accomplishment in the deals he strikes off-camera.

“Frustration’s like anything else, it’s unpleasant and you have to overcome it and find another route to accomplish your goals,” Isakson said. “I’m sure there will come a day when I wake up and say, ‘You know what, I really don’t want to get out of bed today.’ But I haven’t ever had that. I’ve been around 68 years and haven’t had that happen.”