SACRAMENTO — Donald J. Trump is the only candidate left in the Republican primary, yet his campaign schedule is adhering fairly closely to the primary calendar, with him spending the second part of last week and the rest of this week holding rallies across California, which votes on Tuesday.

With an unrelenting sun shining behind him at an airport hangar here on Wednesday, Mr. Trump, the presumptive Republican nominee, hinted at why.

“Sacramento, we’re going to do something. Because I’m going to make a real run in California, all right?” Mr. Trump said to a packed and sweaty crowd, referring to the general election in November. He added: “We’re going to work California hard. We’re going to work the state of Washington hard. We may even work the state of Oregon hard.”

To endear himself to the West Coast voters, Mr. Trump trotted out his usual array of assaults, deriding the likely Democratic nominee, Hillary Clinton, as a politician with “no natural talent.” He again falsely accused her of wanting to abolish the Second Amendment, and attacked her decision on intervening in Libya. Mr. Trump supported the intervention at the time.