Fifty years ago, California was a reasonably Republican state—with a Republican named Reagan on his way to being elected governor, two Republican senators representing the state in Washington, and the pieces in place to back the GOP nominees in the next six presidential elections. Republicans did not always win California, but they had the upper hand. From 1952 to 1988, only one Democratic presidential candidate won the state—and that was Lyndon Johnson, in the Democratic landslide year of 1964.

As recently as 1988, Californians voted for Republican George H.W. Bush for president and Republican Pete Wilson for the US Senate. But that was the end of it. California has not voted for a Republican for the presidency or for the Senate since that year.

This year, the California GOP looks to be headed for disaster in the presidential race, with some recent polls showing Donald Trump gaining less than one-third of the vote. And that’s not the worst of it. The GOP won’t even have a Senate candidate on the ballot.

In a year when control of the Senate hangs in the balance—a year in which both parties are competing feverishly for every advantage—California’s seat is up for grabs. Senator Barbara Boxer, a Democrat who was first elected to the Senate in 1992, is retiring.

But instead of a contest between a Democrat and a Republican in the state that once saw some of the most intensely partisan and politically engaged Senate races in the country, the fight to fill Boxer’s seat will be between two Democrats.

Under California’s nonpartisan “blanket primary” law, which was enacted by the voters in 2010, Tuesday’s Senate primary ballot featured all the candidates on one list. Democrats, Republicans, and several dozen third-party and independent candidates competed against one another in a race where only the top two finishers could earn a place on the November ballot.

That would not have been much of a challenge for a functional Republican Party. But it was an insurmountable challenge for the California Republican Party. Several GOP contenders hit the campaign trail, but none of them got anywhere close to being competitive. They simply split a minority of the vote and languished in single digits.

So the November race will be between Democratic Attorney General Kamala Harris (who ran with strong backing from US Senator Elizabeth Warren, Congresswoman Barbara Lee, Emily’s List, NARAL, and public-employee and teacher unions) and Democratic Congresswoman Loretta Sanchez (who ran with backing from a number of California representatives in the US House, the Latino Victory Fund, and maritime unions). Harris finished well ahead of Sanchez, but neither Democrat was threatened by a Republican.

GOP leaders had plenty of explanations for why they could not get their act together in California. But the fact is that the party has been in decline for a number of years. The national party’s sharp right turn has not helped. But there’s also a local factor with national consequences—especially in this year of Trump.

Two decades ago, Republican Governor Wilson championed California Proposition 187, a 1994 ballot initiative designed to discriminate against undocumented immigrants. The initiative’s proposed restrictions on access to education, healthcare, and social services were draconian, and unconstitutional—as the federal courts eventually determined.

The Republican push for the measure proved to be political folly in a state with a growing Hispanic population and a substantial Asian-American community. The Proposition 187 fight identified California Republicans with anti-immigrant policies, while Wilson’s veto of legislation that sought to prohibit employment discrimination based on sexual orientation fostered additional concerns about the party’s intolerance in a state with a large and active LGBT community.

Wilson was certainly not the sole source of the California GOP’s image problems. But when he left office in 1998, Wilson’s tenure was recalled by The Washington Post as an era of “divisive politics” in which the California governor and his party “championed voter propositions to end affirmative action, social services for illegal aliens and bilingual education.”

Over the past two decades, only one Republican (Arnold Schwarzenegger, an immigrant who frequently broke with his party on social issues) has won a statewide race for president, governor, or US senator. And, if the polls are right about Trump (who trails by 24 points in one recent survey and by 26 in another), no Republican will win a major race this year.

That’s an important reminder for the national Republican Party as it prepares to nominate a candidate who is perhaps best known for his crude anti-immigrant, anti-refugee, anti-Muslim rhetoric. When the embrace of a reactionary candidate identifies a political party with divisiveness and discrimination, the damage to its image does not necessarily end when the candidate quits the field. It can extend for years, even decades, and it can destroy that party’s prospects.