Donald Trump and Republican leaders seeking more of a partnership
Donald Trump is drawing reluctant support from top Washington Republicans now that voters have put him on a glide path to the presidential nomination.
Mr Trump scored two more primary victories on Tuesday night in West Virginia and Nebraska, claiming 92% of the delegates he needs to clinch the nomination.
He has the field to himself, but after having nearly closed the deal with primary voters, the presumptive nominee is facing a Republican establishment that is deeply wary of his candidacy, but has nowhere else to go.
On the Democratic side, Bernie Sanders scored a decisive victory over Hillary Clinton in West Virginia, winning about 51% of the vote to her 36%. But the win did little to advance his fading prospects. Ms Clinton is 94% of the way to the nomination, on track to capture it in early June.
For Mr Trump, the remaining drama is over party discord, not the primaries.
Mr Trump and Paul Ryan are to meet on Thursday, days after the House Speaker - the nation's top elected Republican - withheld his endorsement.
"What we're trying to do is be as constructive as possible and have a real unification," Mr Ryan told a news conference on Wednesday. "We have to be at full strength to win this election."
Asked on Fox News what will happen if the meeting does not go well, Mr Trump said: "We'll trudge forward and do like I've been doing, and win all the time."
There were new signs on Capitol Hill on Wednesday morning that Mr Trump's conservative critics were falling in line.
"As a conservative, I cannot trust Donald Trump to do the right thing, but I can deeply trust Hillary Clinton to do the wrong thing every time," said Trent Franks, adding that he would vote for Mr Trump if that is the choice he has.
Much rides on the relationship Mr Trump forges with the party's leaders. The New York billionaire's bare-bones campaign has glaring deficiencies the party apparatus is uniquely positioned to address. He has largely ignored collecting information on voters he needs to turn out in November, sent few staff to battleground states and taken no steps to build a fundraising network.
"As we turn our focus toward the general election, we want to make sure there's the strongest partnership," Sean Spicer, the Republican National Committee's (RNC) chief strategist, said of Mr Trump.
Mr Trump said he would not rely on public financing, a decision that forces him to quickly assemble a donor network capable of raising the estimated one billion US dollars (£700 million) needed to run a modern presidential campaign. For that, he is likely to have to rely on help from the party's extensive donor network.
"There are many ways that they could work together," said Alabama Senator Jeff Sessions, Mr Trump's top ally on Capitol Hill. "It would be important that they have a good partnership in this election, maybe more than others."
Trump officials were briefed earlier in the week on the RNC's general election operation, which includes a multimillion-dollar voter data operation backed by more than 200 paid staff in key states. Discussions between the Trump campaign and party leaders will continue on Thursday when the presumptive nominee visits Capitol Hill for private meetings.
He is scheduled to meet first with Mr Ryan and the RNC chairman, Reince Priebus, then have a second meeting with Mr Ryan, this time with his House leadership team. Mr Trump is also expected to meet Senate Majority Leader Mitch McConnell.
These are seen as critical steps to address tensions holding back party unity.
Republican leaders in the Senate and at the RNC are urging members to get behind the billionaire and turn their energy toward battling Ms Clinton. House Republicans joined in on Wednesday morning.
Trump supporter Chris Collins said his party's sceptics were beginning to embrace Mr Trump: "They are getting there," Mr Collins said. "They are coming along."
Another Trump supporter, John Fleming, predicted it was "very unlikely" that Mr Ryan would not ultimately back the Republican nominee.
"He wants to unify the Republican Party and it all sort of begins tomorrow," Mr Fleming said of Mr Ryan.
Mr Ryan has said Mr Trump has more work to do to achieve unity.
That was apparent on Wednesday when one of Mr Trump's vanquished rivals, Florida Senator Marco Rubio, suggested he is unlikely to campaign for the nominee because he still has deep reservations about Mr Trump's ideas and conduct.
Even so, Mr Rubio said Hillary Clinton is a worse choice for president and he is "even more scared about her being in control of the US government".