HOUSTON — Charging onto the home turf of their Democratic rivals, Senator Kamala Harris campaigned in Texas for the first time Saturday while Senator Bernie Sanders swung through California — both a test of early strength in a crowded presidential race and a peek at the country’s two biggest states carrying big stakes in 2020.

The timing of Harris’s visit to Houston was hard to miss — the California senator came to Beto O’Rourke’s backyard less than two weeks after the former Texas congressman jumped into the field with massive crowds, heavy cable news coverage, and blockbuster fund-raising.

She chose the rally at Texas Southern University, a historically black campus, to roll out a teacher pay plan that marked the first policy proposal of her campaign. She did not so much as allude to O’Rourke or former San Antonio mayor Julian Castro, the first Texan in the 2020 race, but she drew a packed and diverse crowd in a city that will be the state’s biggest Democratic battleground.

One Texan Harris did reference was former president Lyndon B. Johnson, who she praised while calling for a federal investment in teacher salaries.


‘‘LBJ was actually the last president that made a meaningful investment in public education,’’ Harris said. ‘‘He said famously that the reason to do that was to bridge the gap between helplessness and hope.’’

For Sanders, meanwhile, the Vermont senator was back in California three years after arriving there as a beaten man in the 2016 presidential race. Now he is trying to reawkaen the West Coast donor base and devoted volunteers he built then in the shadow of Harris, the state’s junior senator who has won statewide races in California three times.

Sanders was in Los Angeles on Saturday for the second of three campaign rallies in California.


Although Texas and California are not typical early campaign stops, the lure is both practical and symbolic — both states are delegate-rich, loaded with big donors, and are early on the primary calendar in 2020. But Harris and Sanders are also sending the message they’re not ceding ground in rival territory.

The Democratic stronghold of California is the biggest prize in the primary season, and it’s obvious that Harris plans to win her home state as part of her strategy to become the Democratic nominee.

But Sanders’s string of rallies in the state this week is a reminder that she will have to fight to defend her home turf. And it didn’t appear coincidental that his schedule took him to key battlegrounds San Diego, Los Angeles, and San Francisco.

The Vermont senator made a notable, second-place finish in California’s 2016 presidential primary, when he won 27 of 58 counties. Where you win is especially important in a Democratic presidential contest in the state, because party election rules that divvy up delegates reward candidates who do well in areas thick with Democrats, like Los Angeles and San Francisco.

Harris, who grew up in the San Francisco Bay Area and now lives in LA, has performed strongly in those areas in her three statewide races — she served two terms as state attorney general before going to the Senate.

And it’s those places where Sanders needs to improve on his 2016 showing. In a speech in San Diego Friday, he promised to steal California from Harris in 2020.


‘‘He’s going where the Democratic voters are,’’ said Claremont McKenna College political scientist Jack Pitney.

For candidates on Saturday, the subject of the recently submitted report by Special Counsel Robert Mueller rarely was broached by questioners. Instead, voters mainly asked about health care and school shootings and immigration.

Democratic voters said they cared deeply about the investigation into Russian interference in the 2016 election but weren’t quite sure what to make of the latest twist, exactly.

“We don’t know what’s in it,” said Alane Sullivan, 63, a retired businesswoman, after attending a town hall meeting with presidential hopeful Senator Amy Klobuchar of Minnesota in Rye, N.H. “One thing about people in New Hampshire: They are looking for answers, and they knew she wouldn’t know yet.”

The lack of questions at campaign events about the report surprised some candidates, who had come prepared with lines about the latest development in the nearly two-year investigation.

“I tried to kind of delicately bring it up because I think it is the major issue,” Klobuchar said after her event.

In South Carolina, the one question O’Rourke fielded about the Mueller report came from state Senator Marlon Kimpson, a local Democrat and a host of the event. He asked whether Congress should consider impeaching the president “assuming there’s facts and evidence” that President Trump knew about collusion or coordination with Russians who meddled in the 2016 election.

But others in attendance figured the answers would come later.

“I don’t think you can really process anything right now, because we don’t know what’s in it,” said Amy Drennan, 42, who works for a magazine publisher.


O’Rourke said that the nation should “employ this mechanism of impeachment as an absolute last resort. Ultimately, that will be a decision for our representatives in Congress to make.” But he also said that the matter would “ultimately” be decided “at the ballot box in 2020.”

Material from The New York Times was used in this report.