Presumptive Republican nominee for the U.S. presidential election, Donald Trump, says he is postponing announcing his running mate, a decision scheduled to be unveiled Friday.
Trump tweeted late Thursday that he is postponing the announcement because of Thursday's attack in Nice, southern France, that has taken dozens of lives. He called the attack "horrible."
Earlier Thursday, U.S. media reports said Trump would announce Indiana Governor Mike Pence as his running mate.
Trump, who has never held public office, had also been considering former Speaker of the House Newt Gingrich and New Jersey Governor Chris Christie, who was once a Republican candidate rival of Trump.
Paul Manafort, Trump's campaign chairman, was pushing for Pence, according to the news magazine U.S. News and World Report. Sources within the Trump campaign told the magazine the former U.S. congressman is viewed as reliable and respectable, yet "someone they can control."
Pence is seen as one of Trump's more conventional options in an unconventional political season. Pence spent more than a decade serving in the U.S. House of Representatives before taking office as the governor of Indiana in 2013.
He is known as a social conservative, having signed into Indiana law a measure that protects Indiana businesspeople from prosecution if they choose not to provide services for same-sex weddings. He also recently signed an abortion law that makes it illegal in Indiana to provide an abortion when the fetus has a disability.
Pence is aligned with the tea party movement, a key constituency for a Republican candidate. He also has ties to the Koch brothers, extremely wealthy political donors who have proved a powerful resource for conservative causes.
FILE - Indiana Gov. Mike Pence speaks as his wife, Karen, looks on at the opening ceremony for the Cops Cycling for Survivors fundraising bike ride in Indianapolis, July 11, 2016.
Justin Buchler, a political science expert at Case Western Reserve University, said the Pence pick would make up for Trump's short and inconsistent political record.
"Donald Trump is not really politically conservative," Buchler said. "He doesn't really have a record of advocacy for conservative policy. If you look at his past statements, he has made a lot of liberal statements in the past."
The drawback to the choice of Pence, Buchler said, is that he cannot appeal to the more conservative Republicans and also appeal to independent voters and Democrats. Buchler said Trump "decided that he needed to appeal to the Republican base more than to try to reach out to independents. There's no way to do both."
Sheila Suess Kennedy, law and public policy professor at the School of Public and Environmental Affairs at Purdue University, said Pence will bring Trump credibility, particularly with far-right evangelical Christians. But she says Pence's appeal is narrow.
Pence "is not going to help [Trump] with women, he's not going to help him with progressives of any sort. The only thing I see Pence doing is bolstering Trump with evangelicals," Kennedy said.
She said Pence's focus on religious values is a good balance for Trump's colorful history. "In that sense," she said, “Pence can help." But, she added, many of the people Pence would appeal to are already Trump supporters.
The Republican National Convention will be held next week, July 18-21, in Cleveland.
Meanwhile, presumptive Democratic presidential nominee Hillary Clinton is also interviewing potential vice presidential picks. She is expected to announce her choice next week.
Among the people being mentioned for the role are Virginia Senator Tim Kaine.
FILE - Sen. Tim Kaine, D-Va., speaks with a reporter as he arrives on Capitol Hill in Washington, July 22, 2015. Kaine is on a short list for the Hillary Clinton campaign as a vice presidential candidate.
Clinton insiders told The Hill on Wednesday that Kaine "checks off all the boxes" as a candidate: a strong surrogate on the campaign trail, but someone with whom Clinton can see herself working with once in office.
Also on a list of possible vice presidential choices are Massachusetts Senator Elizabeth Warren, Labor Secretary Tom Perez, New Jersey Senator Cory Booker and Housing Secretary Julian Castro.
Clinton's campaign also was said to be vetting retired Navy Admiral James Stavridis — dean of the Fletcher School of Law and Diplomacy at Tufts University near Boston and a former supreme allied commander of NATO — as a potential vice presidential running mate, a source told Reuters on Tuesday.
The Democratic National Convention takes place July 25-28 in Philadelphia.