WASHINGTON • The widening rift in the US Republican Party has grown deeper and is threatening to upset the July nomination convention, as Mr Donald Trump refused to rule out blocking Mr Paul Ryan, the Speaker of the House, from serving as the convention's chairman.
Mr Trump's warning was his latest affront to Republicans who have urged him to adopt a more cooperative and unifying tone. And it amounted to an extraordinary escalation in tensions between the party's presumptive nominee and its highest-ranking office-holder.
In a series of television interviews on Sunday, Mr Trump demonstrated little interest in making peace with party leaders, like Mr Ryan, who have called on him to more convincingly lay out his commitment to the issues and ideas that have animated the conservative movement for the last generation.
"I am going to do what I have to do - I have millions of people that voted for me," Mr Trump said on ABC. "So I have to stay true to my principles also. And I am a conservative, but don't forget, this is called the Republican Party. It is not called the Conservative Party."
If anything, Mr Trump's candidacy has thrived because of his resistance to party politics as usual, not despite it. He has broken with Republican leadership in Congress on trade, military intervention and immigration policy. And he appears determined not to fall in line, having effectively secured the nomination.
Mr Trump's differences with those in the party who think they have earned more of a right to set its political and ideological course have led to a rupture at the time when Republicans would ordinarily be trying to put the personal clashes of the primary contests behind them.
These divisions have played out most openly and vividly around the planning of the Republican National Convention. It is a telling reflection of the state of Republican politics: an escalating spat over a party for a party that is coming undone.
Four of the last five Republican presidential nominees - Mr George H.W. Bush, Mr George W. Bush, Mr John McCain and Mr Mitt Romney - have said they will skip the convention in Cleveland, where Mr Trump is expected to be nominated.
Mr Ryan, who serves as the convention's ceremonial chairman, has made the provocative declaration that he is not ready to support his party's likely nominee, a rebuke that drew Mr Trump's threat to keep him from assuming that role. Mr Trump and Mr Ryan are set to meet privately in Washington on Thursday as part of an effort to bridge the gap between the party establishment and Mr Trump.
The large corporations that usually fund both parties' conventions are wary of becoming involved and are holding back on sponsorships, leaving Cleveland about US$7 million (S$9.5 million) short of its US$64 million fund-raising goal.
With Mr Trump's two remaining rivals, Senator Ted Cruz of Texas and Governor John Kasich of Ohio, out of the race, Republicans have defused a bitter fight for the nomination played out on TV. But they seem to be heading for another.
Questioning Mr Trump's conservative credentials, some Republicans are making demands that are unheard of for the party's standard-bearer. Conservative activists want him to identify before the convention people he would appoint as Cabinet members, Supreme Court justices or even vice-president.
And how to handle Mr Cruz - and the hundreds of delegates pledged to vote for him - is another sensitive issue. Without an agreement with the Trump campaign, Mr Cruz's nearly 600 delegates could vote against Mr Trump in an embarrassing show of discord.
There is the question of discord in the streets as well, with masses of anti-Trump demonstrators expected to descend on Cleveland.
NEW YORK TIMES