U.S. Rep. Dana Rohrabacher was a 41-year-old ex-speechwriter for Ronald Reagan when he first won election to his coastal Orange County Congressional seat in 1988.

Now 70, with three decades of national politics under his belt, he’s facing the toughest fight of his career – a bare-knuckled battle where fresh-faced Democrats and a well-known local Republican alike are denigrating his legacy while grappling to take him down.

And for the first time in 15 terms, Rohrabacher, a perennial shoo-in, might finally have cause to worry about his incumbency.

Political handicappers rate the contest a toss-up. Rohrabacher’s 48th Congressional District swung narrowly to Hillary Clinton in 2016, causing Democrats to target the newly-competitive seat as one of 23 they need to retake control of the House of Representatives.

Meanwhile, several prominent GOP politicians have jumped ship to back the congressman’s Republican challenger, former Orange County GOP Chairman Scott Baugh, questioning Rohrabacher’s efficacy and saying it’s time for a change. And in the ongoing investigation into Russian interference in the 2016 election, Rohrabacher’s name has surfaced several times for his meetings with people connected to the Kremlin.

Amid the fracas, Rohrabacher has jumped on the offensive.

He’s campaigned harder than ever, attacking Baugh, a former protégé, with a slew of disparaging ads and mailers. He’s brushed off the Russia probe as a sham, saying that local voters care more about his record opposing taxes and deficit spending than about Moscow. And he’s made a fractious, hard-line anti-illegal immigration message the core of his campaign, saying in an interview with the New York Times that his constituents “are concerned about illegal immigrants coming into their neighborhood and raping people.”

“Millions of more people coming here illegally, consuming these resources, is the greatest threat” to the well being of Americans, Rohrabacher said at a March meeting of the Orange County Board of Supervisors shortly after Baugh entered the race.

Related: Rohrabacher says it’s OK to not sell homes to gays

But Baugh and the contest’s leading Democratic candidates – businessman Harley Rouda and stem-cell biologist Hans Keirstead – all say the congressman’s track record demonstrates an inability to wield his seniority. They also see a disproportionate focus on out-of-district issues, such as improving foreign relations with Russia and advocating for the marijuana industry.

“His lack of leadership in getting bills passed and adequately representing his constituents is a huge issue that everyone running recognizes,” Rouda said.

Added Keirstead: “This is the first time that Rohrabacher has been exposed for his terrible record of doing little and doing things that don’t represent the district.”

All-GOP November?

Despite being attacked from all sides, most polls show Rohrabacher is a favorite to get through the June 5 primary to a November runoff. That means the June contest could be primarily a competition between the other 11 active candidates for the second spot in the General Election, when the congressman could be more vulnerable.

Democrats are hoping to ride anti-Trump sentiment toward flipping the Republicans stronghold, where both GOP candidates have linked themselves closely to the President. But Baugh’s candidacy makes the race for Rohrabacher’s seat perhaps the most likely congressional contest in California to have an all-GOP November ballot. That outcome is feasible under the state’s jungle primary system, which advances the top two finishers, regardless of party.

The 48th Congressional District – which stretches from Seal Beach to Laguna Niguel and inland to portions of Westminster and Santa Ana – has a voter pool that skews older, whiter and more Republican than other competitive Orange County seats, according to Political Data Inc.

The GOP holds a 10 percentage point voter-registration advantage over Democrats in the district, amounting to a 40,000-person lead. And during the past two election cycles, Rohrabacher has won by a 22-point average margin of victory. That Republican advantage could supply enough votes to squeeze Baugh into the top two, especially if the five active Democratic candidates collectively dilute the left’s vote.

On the other hand, Democratic turnout nationwide has been higher than usual in contests since Trump was elected. And a quarter of district voters are registered as “no party preference,” a group that has skewed overwhelmingly Democratic in recent elections – meaning that if there’s high turnout, Democrats stand a chance.

Democrats swap endorsements

Fearing a November lockout, Democratic candidates have raised substantial sums, and national Democrats have flooded the district with mailers and TV ads, causing Republicans to follow suit.

In all, the contest’s candidates have raised at least $7.4 million, placing it in the top 10 of all active House races in the nation, according to the Federal Election Commission and Opensecrets.org. Additionally, nearly $2.2 million has been spent from outside sources on independent expenditures in the district, one of the five highest marks in the country.

The largest chunk of outside money has gone toward attacking Baugh, a former assemblyman, in an attempt to unite the Republican vote behind Rohrabacher so that his GOP challenger doesn’t make the runoff. The Democratic Congressional Campaign Committee (DCCC) has spent more than $1 million on that effort. The DCCC has further interceded since mid-May by backing Rouda and making a joint TV ad with his campaign, all in an effort to similarly consolidate Democratic voters behind a single candidate.

Rouda also has snagged endorsements from the local chapter of the anti-Trump grassroots group Indivisible, three Democratic candidates who withdrew from the race, and several local Democratic members of Congress, including Linda Sanchez, Lou Correa and Alan Lowenthal.

The DCCC’s choice to back Rouda stands in opposition to the California Democratic Party, which in February endorsed Keirstead. The intraparty rift has caused friction, prompting California Democratic Party Chair Eric Bauman to warn the DCCC to “tread carefully.”

“Decisions that undercut the independence or our endorsed candidates have the potential to be extraordinarily counterproductive.”

Rouda’s opponents have pointed out that he was a registered Republican until 1997. He became an independent for the next two decades but still donated $1,000 to Republican John Kasich in the 2016 presidential election. Rouda said he switched parties because Democrats better reflect his values and has voted for the Democratic presidential nominee since 2004. In turn, Rouda has questioned Keirstead’s political past, noting that his opponent has never voted in a primary election, leading Keirstead to respond that he’d “been busy.”

But when it comes to the issues, the two Democratic favorites have nearly identical platforms. Both support Medicare for all, bans on assault rifles and bump stocks, universal background checks on gun purchases, immigration reforms modeled after plans that died during Obama’s presidency, pre-K for all, and investment in green energy. And they’ve both slammed Rohrabacher for his May 2017 vote to repeal Obamacare.

A third Democrat, trial lawyer Omar Siddiqui, a self-described “Reagan Democrat” and a Republican until 2009, hasn’t gained much traction in the polls. But he has raised $933,000 – largely behind $750,000 in self-funding – raising the prospect that he could impact the contest.

GOP friends turned enemies

Baugh has been gearing up to run for Rohrabacher’s seat for two years, after he said the congressman announced in a private meeting that he planned to retire at the end of this term. With that in mind, Baugh raised $500,000 for the contest in the first quarter of 2016. But Rohrabacher denied making such a promise and called on Baugh to return money to donors who might not have known it eventually would be used to challenge the congressman.

And just like that, the longtime friends morphed into public foes.

After Baugh decided to run for Congress in March, prominent Republicans asked him to withdraw in a letter signed by two dozen GOP politicians, including House Majority Leader Kevin McCarthy, U.S. Reps. Mimi Walters and Darrell Issa, and Republican Party of Orange County Chairman Fred Whitaker. But other well-known Republicans – such as state Senators John Moorlach and Pat Bates – refused to sign, with Moorlach saying he couldn’t recall any legislative accomplishments that Rohrabacher had made in three decades.

Since then, Rohrbacher’s campaign war chest has been spent almost exclusively on assailing Baugh. In TV ads and mailers, the congressman accused Baugh of being a lobbyist for the unpopular sober living home industry, supporting amnesty for illegal immigrants, and being a “never Trumper” – attacks that highlight the pro-Trump and anti-illegal immigration platforms that have dominated the GOP side of the race.

Baugh called the claims outright fabrications and asked the county GOP to censure Rohrabacher. Baugh said he represented a sober living home operator briefly but only after the city of Newport Beach asked him to advise the company to voluntarily restrict the concentration of its facilities. He said he supports the President. And he said he has never advocated for amnesty – instead pitching a plan to secure the border, strengthen employer verification, deport people in this country illegally who have committed a crime, and establish a limited work-permit program for some undocumented immigrants.

“I think when you don’t have a record to run on, you resort to smears,” Baugh said of Rohrabacher. “We need fresh blood, fresh ideas, fresh perspective.”

One issue where the two GOP competitors differ is on offshore drilling, which Rohrabacher has supported and Baugh opposes in California. Another is Trump’s tax overhaul, which Rohrabacher voted against, noting it would “raise taxes for many of my constituents… by eliminating the deductibility of property taxes, income taxes and paid sales taxes.” Baugh said he would have supported the tax overhaul but would have fought to retain those deductions.

The recent fighting between the two men is the latest chapter in their intertwined pasts. Rohrabacher first recruited Baugh in 1994 to run for state Assembly, with the two even operating out of the same office. Following that race, Baugh and Rohrbacher’s wife were both charged criminally for a ploy to recruit a decoy Democratic candidate to split the left’s vote. Rohrabacher’s wife pled guilty while the charges against Baugh were dropped.

Now, as the two go head to head, Rohrabacher remains confident he’ll be the one left standing in November. And he’s fundraising for a long fight: the congressman recently announced a $2,700-per-person dinner in support of his campaign on the night of June 3 – two days before the primary.