WASHINGTON — Donald Trump became the last man standing in the race for the Republican presidential nomination on Wednesday as his sole remaining rival, John Kasich, ended his campaign, and he now faces the challenge of repairing deep fissures in the party.

Anointed the presumptive nominee after winning Indiana on Tuesday and driving his closest rival, Sen. Ted Cruz, from the race, the 69-year-old New York billionaire planned to set up a vice presidential selection committee and step up efforts to seek unity among a wider group of Republicans ahead of the Nov. 8 election.

Kasich, the Ohio governor, had stayed in the race in hopes of persuading Republicans to choose him as the nominee at a contested convention in July. He ended his campaign as a clear path emerged for Trump to amass the delegates needed to secure the nomination outright.

“As I suspend my campaign today, I have renewed faith, deeper faith that the Lord will show me the way forward and fulfill the purpose of my life,” Kasich said in Columbus, the Ohio state capital.

Some Republican lawmakers said they would support Trump since he will be the nominee, stressing the importance of defeating Democrat Hillary Clinton in the general election. One of those was 2008 presidential nominee John McCain, a senator from Arizona who is seeking re-election this year and was insulted by Trump last year.

“As John McCain has said, he will support the nominee of the Republican Party, who is now presumptively Donald Trump,” said McCain’s Senate campaign spokeswoman, Lorna Romero.

But the wounds from a brutal primary battle were still raw among many Republican loyalists who simply cannot bear to support Trump because they worry he could spell disaster for the party in November.

Republican Sen. Ben Sasse of Nebraska reiterated statements that he would not back Trump and pointed to a February Facebook post in which he said he would look for an alternative candidate if Trump became the nominee.

Nebraska’s other U.S. senator, Republican Deb Fischer, made clear in an interview with Nebraska Radio Network that she would support the party’s nominee but was not comfortable with Trump.

“Mr. Trump is going to have to work hard to bring the party together,” she said. “He’s going to have to work hard to explain his stance on different issues and to talk about the principles and values he holds. I look forward to having a robust race here.”

Republican Sen. Susan Collins may be throwing cold water on the idea she could be Trump’s running mate in the presidential race but that doesn’t mean she is ruling out supporting him.

On Wednesday morning, she was heard on a WGAN radio show saying she could back Trump if he stopped the “gratuitous personal insults” and “bizarre” behavior.

Collins also said she wants to hear more specifics on what a Trump presidency would look like.

Collins, who backed Jeb Bush early in the contest, said she wasn’t waiting by the phone for Trump’s call to join the ticket.

“I don’t think this is a decision that I will be confronted with making,” she said.

Collins said she always has supported the Republican nominee for president. “I suspect I would do so this year, but I do want see what Donald Trump does from here on out.”

South Carolina’s Republican governor, Nikki Haley, issued a statement saying she would support the Republican nominee but was “not interested” in being the party’s vice presidential running mate.

Since launching his White House bid last summer as a long shot amid a crowded field that included governors, former governors and senators, Trump repeatedly defied predictions that his campaign would implode.

He prevailed over rivals he derided as “grown politicians,” despite making provocative statements along the way that drew sometimes furious criticism from many in the party but fed his anti-establishment appeal.

His supporters have been wildly enthusiastic about his “America First” platform, which has strayed far from some conservative bulwarks like free trade and military interventionism.

In a series of Wednesday morning television interviews, Trump made clear he would not be looking to placate everyone after a tumultuous primary campaign in which many establishment Republicans rallied around Stop Trump and Never Trump movements.

Party loyalists have been appalled by the bombastic, bullying style of the former reality-television star, his denigrating comments about women and his proposals to build a wall on the border with Mexico and deport 11 million illegal immigrants.

“I am confident that I can unite much of it, some of it I don’t want,” Trump said on NBC’s “Today” show. “Honestly, there are some people I really don’t want. People will be voting for me. They’re not voting for the party.”

The New York Times quoted Trump as saying he would soon form a team to help him in the search for a vice presidential nominee to be announced in July. He put retired neurosurgeon Ben Carson on the committee. Carson, who like Trump has never held elective office or served in government, endorsed Trump after pulling out of the Republican presidential race earlier this year.

Trump, who has honed an ‘outsider’ image, suggested he might make a more conventional choice as his running mate.

“I’m more inclined to go with a political person,” Trump told the Times. “I have business very much covered.”

Trump’s win in Indiana cleared the way him to prepare for a likely match-up in the November election against Clinton, a former secretary of state. She lost the Indiana primary to tenacious challenger Sen. Bernie Sanders, but remains on course to become her party’s nominee.

Republican National Committee Chairman Reince Priebus called Trump the party’s presumptive nominee in a tweet on Tuesday night, saying: “We all need to unite and focus” on defeating Clinton.

In an interview on Wednesday, Priebus acknowledged achieving Republican unity would be difficult. “It’s going to take some time but we’re going to get there,” he said on CNN.

Support for Trump among Republicans jumped nationally in recent weeks to the highest level of the primary campaign, according to Reuters/Ipsos polling. A recent poll found Trump with the support of 53 percent of Republican participants, well above Cruz at 25 percent. Kasich had 16 percent.

In a potential general election contest, however, Clinton led Trump by about 10 percentage points among likely voters. The poll included 623 Democrats and 556 Republicans and had a credibility interval of 5 percentage points.

Clinton called Trump a “loose cannon” on Wednesday and said America should not take a risk on an unreliable candidate.