Two months later, the downside of Gov. Brian Kemp's decision to hold a statewide, all-comers application process to replace U.S. Sen. Johnny Isakson has become obvious.

When it debuted in September, the novel approach won national plaudits, even from Democrats.

The online “portal,” as it was dubbed, enhanced Kemp’s first-year reputation as a governor who campaigned as a hard-core conservative – but whose appointments have showcased a willingness to broaden the Republican tent.

Yet politics abhors a vacuum, and Isakson’s Dec. 31 retirement date quickly approaches.

On Wednesday, U.S. Rep. Doug Collins, R-Gainesville, in an apparent attempt to force Kemp’s hand, let it be known that he intended to mount a 2020 campaign for Isakson’s seat — against the governor’s pick if necessary.

Hours later, the real hammer fell. President Donald Trump personally rang up Kemp and urged him to name Collins, who has been his chief defender on the House Judiciary Committee, to a Senate that could soon serve as his jury in an impeachment trial.

Don Jr. quickly joined in, via Twitter. “@RepDougCollins is a fighter and exactly the kind of person Republicans should want in the senate. We need someone who gets it,” the president’s son tapped out.

The irony is so palpable that you can almost taste the rust.

Last year, as secretary of state, Kemp won a landslide GOP primary runoff for governor over Lt. Gov. Casey Cagle, largely due to a last-minute Twitter endorsement from Trump.

Now Kemp is a governor who could soon find out what life is like on the wrong side of a presidential Tweet. In one sense, which we will get to in a few paragraphs, the situation might be called “Cagle’s revenge.”

The largest share of blame for Kemp’s dilemma can be traced to the two cross-currents that have roiled the Republican firmament since his Senate competition began — each calling out for contrary responses.

First, November happened. In Virginia, Kentucky and most recently in Louisiana, suburban voters – women in particular — deserted the Republican cause.

In Virginia, Democrats took total control of the state legislature for the first time in a generation. In Kentucky, a unpopular GOP incumbent governor who tied himself closely to Trump was ousted. In Louisiana, a Democratic governor won re-election, despite three visits to the state by the president on behalf of the Republican challenger.

For a Georgia governor who faces similar revolts in north metro Atlanta, those election returns argue for an Isakson replacement who might support Trump, but isn’t closely identified with the president. Preferably a woman.

Then we have the House impeachment inquiry.

Over the last two weeks, public hearings have greatly increased the gravity of the situation, as a parade of White House and State Department officials — former and current — have outlined in detail an effort by President Trump to extort a political favor from Ukraine.

To a GOP base commanded by Trump, that calls for increased loyalty — not distance. On Wednesday, in an interview with the AJC, Collins made clear that he would remain a staunch defender of the president. Later that day, the congressman was interviewed by conservative Hugh Hewitt, the nationally syndicated radio host.

We don’t know who Governor Kemp has in mind to replace Isakson in the Senate. But Collins clearly doesn’t think its him. In that radio interview, Hewitt endorsed Collins’ bid — because of the likelihood of a Senate trial. Then he asked Collins about his conversations with Kemp.

“Well, at this time, I would assume that the governor will get with me. He’s not got with me at this point, so we’ll see if he chooses to,” Collins replied.

U.S. Sen. David Perdue, who faces re-election in 2020, is a third interested party watching the situation.

In an interview with GPB “Political Rewind” host Bill Nigut, Perdue expressed on-the-record patience with the governor’s selection process, but underlined his concern. “Here’s the bottom line – whoever the governor picks will be my running mate,” Perdue said.

But Kemp will be picking his own running mate as well. Whoever fills Isakson’s shoes will be on the November 2020 ballot – the likely first stage of a “jungle” contest that includes both Democrats and Republicans. The winner will then need to run again in 2022, for a full six-year term.

More than 500 others have applied for Isakson’s seat, so it is significant that Collins and Trump began publicly applying pressure only after Kelly Loeffler, a financial executive who co-owns Atlanta’s WNBA franchise, submitted her name.

Governors and members of Congress aren’t just individuals. They’re leaders of teams. Some members of these teams are unpaid volunteers. A very few are paid, very well, for producing the most expensive assets in a campaign – TV ads, mailers and polls. They have influence with their leaders, whether members of Congress or governors.

In the midst of a Collins-Kemp fracas, a mostly retired political operative reminded me of that time when Gov. Roy Barnes appointed former Gov. Zell Miller to replace U.S. Sen. Paul Coverdell, who had died suddenly in 2000 of a brain aneurysm.

The decision was controversial, and Barnes ultimately came to regret it. But at the time, opposition on the Barnes team was somewhat assuaged by the fact that Miller’s political team – Paul Begala and James Carville – had moved on to other pastures.

Miller’s campaign for a full term was handled by members of Barnes’ political team. Miller’s campaign contributions flowed through them. Peace reigned.

Rival teams can exist within individual parties. In terms of polling, TV ads, mail printing and polling, a Venn diagram would show heavy overlaps when it comes to the professional teams that once stood behind Gov. Nathan Deal and Lt. Gov. Casey Cagle, and now stand behind Collins.

It is a Hall County thing. And remember that Deal endorsed Cagle in that 2018 GOP primary runoff against Kemp. Collins pointedly stayed neutral in the gubernatorial contest.

Loeffler is a multimillionaire whose husband heads the Intercontinental Exchange, the giant financial trading platform that bought the New York Stock Exchange.

She can self-finance not just one, but two Senate campaigns that are likely to set fundraising – and spending – records in two consecutive cycles.

Should she become Kemp’s pick for the U.S. Senate, it would surprise no one if she relied on the governor’s political team for professional advice and counsel.

So yes, the fight over Johnny Isakson’s Senate seat, at the 30,000-foot level, is about the survival of a U.S. president and suburban woman who are growing ever more wary of the man.

But at the ground level, it’s also about team rivalry, cash, and a continuation of the 2018 Republican race for governor.