By Doina Chiacu and Emily Stephenson
WASHINGTON (Reuters) - Indiana Governor Mike Pence will endorse Republican White House hopeful Ted Cruz on Friday ahead of the state's primary next week, media outlets reported, while front-runner Donald Trump looked to California after demonstrations at a rally there on Thursday.
Cruz hopes a win in Indiana's presidential nominating contest on Tuesday will help him deprive Trump of delegates to the Republican National Convention in July and keep Trump from securing the nomination for the Nov. 8 general election.
Cruz, who has lost primaries in Northeastern states, told reporters on Friday that he did not know if Pence would endorse him but said he respected the governor, whose approval ratings fell in 2015 after he signed controversial "religious freedom" legislation.
Neither Pence nor Cruz representatives replied to Reuters requests for comment.
Trump visited California ahead of its June 7 primary, when the most convention delegates of the Republican nominating cycle will be at stake. He planned to speak to the state Republican convention on Friday.
About 20 people were arrested on Thursday night near the county fair grounds in Costa Mesa, California, where Trump held a rally. Local media reported that protesters smashed the window of a police patrol car and blocked traffic.
The head of California's Republican Party on Friday downplayed the demonstrations, and said protests were typical for the state's politics.
"If you're a Republican running for president in California and you don't get protested, you're doing something really, really wrong," Jim Brulte, chairman of the California Republican Party, said on CNN on Friday. "Every president I've campaigned with here in California has been protested."
Protests have become common outside rallies for Trump. His campaign had to cancel a rally in Chicago last month after clashes between his supporters and protesters.
Trump has won a broad following among Republicans in the United States, along with ardent critics, for his stand on illegal immigration. He has accused Mexico of sending drug dealers and rapists across the U.S. border, and promised to end it by building a wall and making Mexico pay for it.
The population of Costa Mesa, where he appeared on Thursday, is about a third Latino.
Trump appeared at the rally with families of several people who were allegedly killed by undocumented immigrants.
Local news afterward showed demonstrators surrounding vehicles, waving Mexican flags and holding signs. At least one demonstrator was shown jumping on top of a police car.
(Reporting by Doina Chiacu and Timothy Ahmann in Washington and Brendan O'Brien in Milwaukee; Writing by Emily Stephenson; Editing by Richard Valdmanis, Alistair Bell, Toni Reinhold)