MADISON - U.S. Sen. Ron Johnson rode to Washington, D.C., nearly a decade ago as anyone but a career politician and was re-elected after promising to leave office after just two terms.

But now Johnson is embracing his new role as the leader of Wisconsin's Republican Party and is mulling a third term or even a bid for governor.

That's because on the morning of Nov. 7, the U.S. senator from Oshkosh woke up as the only Republican representing the entire state of Wisconsin to survive the election the night before. The "last man standing," as he calls it.

"When I noticed Scott Walker didn't win, nor Brad Schimel or obviously the lieutenant governor, I realized I was the last statewide representative," Johnson, who wasn't on the November ballot, said in an interview with the Milwaukee Journal Sentinel. "It's a role I never sought, but it's a responsibility I take pretty seriously."

Johnson, 64, is establishing himself as the top state Republican after first being elected in 2010 despite practically no ties to the so-called establishment he now guides.

Once pledging to step away from politics after two terms, Johnson now won't say what he'll do once his second six-year term ends in 2022.

Sources with knowledge of Johnson's plans say the senator is contemplating a choice: Whether to seek a third term in the U.S. Senate, run for governor of Wisconsin (or do neither and return to Oshkosh).

Johnson isn't saying which path he'll choose, but he's also not ruling out any of the scenarios.

Instead, when asked, Johnson says he's "completely focused" on electing Republicans in Wisconsin during the 2020 elections by creating what he calls a "grassroots juggernaut."

Trump on Johnson: 'Wisconsin Tough'

Johnson's new position as the state's top Republican was on display at an April 27 rally in Green Bay for President Donald Trump, who called Johnson "Wisconsin Tough" during his speech and departed Air Force One with Johnson at his side.

Jennifer Duffy, senior editor for The Cook Political Report who covers Senate and governor races, said Johnson is taking on the role "because he has to."

"So you might as well roll up your sleeves and do the work," Duffy said in an interview.

Duffy said it's not unusual for members of the U.S. Senate to back off a previous pledge to limit the number of terms they will serve, in part to avoid being viewed as a lame duck and keep potential challengers at bay.

"It's hardly unprecedented," Duffy said. "It occurs to some of these members that the Senate is based on a seniority system and therefore it takes some time to build that seniority and get things done."

It's unclear whether Johnson would have more or less clout in the U.S. Senate if he won and served a third term. Johnson became chairman of the Senate Committee on Homeland Security and Governmental Affairs in his first term and is limited to serving in the leadership role for six years.

Assessing election losses

Johnson's focus comes after statewide Democratic victories that swept Walker, Schimel and Lt. Gov. Rebecca Kleefisch from office. Former House Speaker Paul Ryan had retired and Reince Priebus was no longer in the White House.

At the same time, Republicans maintained strong majorities in the state Legislature, creating an opportunity for Johnson to assume what he calls the "titular head of the party."

He said his first phone call was to Priebus, who served as Trump's chief of staff for about six months and who was chairman of the Republican National Committee from 2011 to 2017 and chairman of the state's Republican Party from 2007 to 2011. The two planned an autopsy of the 2018 election, he said.

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Johnson said a key conclusion is the statewide campaigns, like Walker's, fell short in engaging with county GOP groups and other local-level organizations.

"Longtime volunteers just didn’t have the kind of in-depth contact with the statewide campaigns," Johnson said. "When you’re sidelined in the process, you’re probably less engaged."

Neglecting the grassroots

Johnson said he found the 2018 campaigns to be "ad-driven and consultant-driven" as opposed to relying on "grassroots efforts."

For example, Walker released nearly 40 web-based and television ads over the course of his re-election campaign, including one that was produced to run only on gas station pump screens.

"You need ads," Johnson said, acknowledging the influence large ad buys around the state can have on elections — including his. But, he said, the party is focusing on feedback he received from county party leaders suggesting consultants controlled the campaigns and local groups "really didn’t feel like they were listened to."

Mark Jefferson, the executive director of the Republican Party of Wisconsin, said the party's analysis of the 2018 races showed the local-level organizations had received less attention and there was less infrastructure in place than in recent years.

"I had seen what it had been in the past and it just didn't seem that we were in that same place," Jefferson said.

Jefferson said small investments in local-level groups "can really pay big dividends" rather than buying "another round of expensive television ads."

"We need to get back to that," Jefferson said.

Bob Dohnal, a longtime Republican activist who puts together the Wisconsin Conservative Digest, said: "Wisconsin is the place where people say, 'Gee, I don't know if I can vote for the guy — I've only met him four times.'"

"You just cannot get elected by sitting and spending millions of dollars," he said.

Johnson said he wants more training and more recruitment and not leaving "any line on the ballot unopposed."

"I come from outside the political process," Johnson said. "I was never really enamored with political consultants — I'm not a big fan — so it's not surprising if I have the titular leadership of the party, I'm going to focus on what I think works best."

In a statement, Walker didn't directly address Johnson's comments about how his campaign interacted with local groups but said he is "grateful to our hard-working grassroots supporters who helped us win elections in 2010, 2012 and 2014."

RELATED:An erosion of support in diverse set of cities and suburbs spelled defeat for Scott Walker

Walker noted that in 2018, local groups helped him receive about 34,000 more votes than in 2014. Walker's campaign also reported in June that he tripled the number of "grassroots events" Walker attended when compared with his second run for governor.

Walker also said support among "the grassroots" helped elect his former chief legal counsel and state appeals court judge Brian Hagedorn to the state Supreme Court in April.

"Looking ahead to 2020, we will need to continue to find ways to engage the grassroots in Wisconsin,” Walker said.

RELATED:Lisa Neubauer concedes Supreme Court race, prepares Appeals Court re-election bid

2018: A Democratic surge

But the national environment also was not friendly toward Republicans ahead of the general election — with many political observers citing the April 2018 landslide election of liberal-leaning Rebecca Dallet to the Wisconsin Supreme Court as evidence of a wave of Democratic enthusiasm.

R.J. Johnson, a longtime Republican strategist who once worked as Walker's top adviser, said the outcome of the 2018 election in Wisconsin was a result of the national trend: a surge of Democratic turnout that topped turnout among Republicans who had less enthusiasm on their side — which is not an unusual environment for a midterm election.

"Moreover, the failure of our leaders to deliver on their key promises, despite control of Congress and a Republican president, was a significant contributor to lessened GOP enthusiasm," said R.J. Johnson, who is not related to Ron Johnson.

"This was evident at grassroots events across Wisconsin and nationally in the 2018 campaign. People simply were not turning out in the same numbers. One can psychoanalyze the tactics, but when it happens across the board it’s probably less about what did (or didn’t) happen here."

RELATED:Wisconsin undergoes striking political shifts, even as it remains a 'purple' battleground

Former Republican Gov. Tommy Thompson said it would be an "oversimplification" to attribute Republican losses to an over-reliance on consultants and said Walker traveled the state extensively to build local support following his failed presidential run in 2015.

"You can blame it on a lot of things, but the truth of the matter is the Democrats were better organized in this election than we were — without a doubt," Thompson said.

R.J. Johnson said a tactical focus on local-level groups also needs enthusiasm among the groups' members to make gains, citing the unexpected election of Hagedorn to the state State Supreme Court this year.

"Driven by a perceived attack on Hagedorn’s religion, Christian voters lit up statewide bringing volunteers out in droves," he said. "Was that caused by a tactical focus on the grassroots by the campaign, or was it a higher level of motivation? I’d argue it was the latter and gave the conservative an upset victory. It’s why I think polls have been so far off lately. They are unable to pick up on the emotional momentum of different groups."

Hagedorn defeated state appeals court judge Lisa Neubauer, favored by liberals, after a groups that typically spend on behalf of conservative judicial candidates withdrew support after learning Hagedorn had founded a school that allows the expulsion of students in same-sex relationships or who have parents in same-sex relationships.

Following Dallet's sweeping victory a year before, and Democratic wins statewide in the general election, political observers leading up to the April election predicted similar enthusiasm on the Democratic side would give Neubauer the advantage.

"Could more emphasis on the grassroots have changed the outcome? Maybe," R.J. Johnson said of the 2018 general election. "But you can’t lose sight of what made the race as close as it was: a national political gravitational pull where the Wisconsin GOP was only able to nibble around the edges."

ACA remains an issue

Democrats, however, see the 2018 Republican losses as voters rejecting GOP policies. It wasn't a failure of effort but a disconnect with voters on their most valued issues, Democratic Party of Wisconsin Chairwoman Martha Laning said.

"What happened in 2018 is something we want to build on," Laning said in an interview. "We talked about the issues that are most important to voters. In particular, health care. And that is an issue Ron Johnson is on the wrong side of."

Whether Wisconsin residents with pre-existing conditions would continue to be covered by health insurers should the Affordable Care Act be overturned was a central debate to the 2018 races.

Walker and Schimel were heavily criticized by their opponents during the race over joining a federal lawsuit to overturn the law.

Johnson is opposed to the ACA but supports keeping coverage for pre-existing conditions.

RELATED:Judge lets Wisconsin out of two Obamacare lawsuits, handing Gov. Tony Evers a victory

In a December telephoned town hall, Johnson noted his daughter has a congenital heart defect and that he doesn't see keeping the protections as up for debate.

"The good news is that there are ways of covering people with pre-existing conditions without causing premiums to double, triple and quadruple, which it’s the faulty architecture of Obamacare that has caused that," Johnson said.

But Laning said it's Johnson's participation in crafting plans to replace the ACA that will continue to draw criticism.

"He has cast votes against the Affordable Care Act and I think that's a big concern," she said.