Republican ticket likely to come down to horse-trading in Cleveland

"I warned that the Republican Party is in real danger of subversion by a radical, well-financed, highly disciplined minority," the Republican governor told his party's supporters in a packed convention hall, struggling to be heard over his booing opponents.

No, it wasn't Donald Trump or Ted Cruz the governor was referring to. This was 1964 and New York governor Nelson Rockefeller, the poster boy of the Republican Party's moderate wing, warning an angry national convention about the rise of nominee-in-waiting, conservative US senator Barry Goldwater.

The uncertainty around whether Trump will reach the 1,237 delegates needed to be the Republican nominee in November’s election has led many to trawl their history books to see how past contested primaries have played out, and 1964 has figured prominently in that search.

The last time a Republican race went to the convention without the nominee being picked in the primaries was, in fact, more recent than that. It was 1976 and President Gerald Ford was challenged by Ronald Reagan. Backroom deals and a horse-trading for delegates ultimately won Ford the nomination on the first ballot but the fight hobbled him and he lost to Jimmy Carter later that year.

The 1964 convention involved the same kind of division Republicans are witnessing in this campaign between Trump, Cruz and Ohio governor John Kasich. Not since Goldwater has the Republican establishment so railed against a candidate as it has against Trump and, to a lesser extent, Cruz. The billionaire so terrifies the leadership that Cruz, the Texas senator the establishment has so hated since the 2013 government shutdown, is now their official alternative.

Republican South Carolina senator Lindsey Graham, himself a one-time presidential candidate this year, summed up Cruz's unpopularity best: "If you killed Ted Cruz on the floor of the Senate and the trial was in the Senate, nobody would convict you."

Some Republican establishment figures, such as 1996 nominee Bob Dole, even preferred Trump over Cruz because the billionaire could work with Congress. "He's kind of a dealmaker," Dole said. Since then, as candidates have dropped out and Cruz has emerged as the only real winner besides Trump, more and more Republicans are backing him.

In their eyes, Cruz is no longer the evil of two lessers, but the lesser of two evils.

Opposition to Goldwater matched the fear Trump has generated within the party establishment. Rockefeller warned that the Arizona senator's policies could "spell disaster for the party and the country". Republican governor William Scranton called Goldwaterism a "whole crazy-quilt collection of absurd and dangerous positions". Governor George Romney (Mitt's father) said Goldwater's nomination would lead to the "suicidal destruction of the Republican Party".

In the end, Goldwater easily won the nomination but lost heavily to Lyndon Johnson in one of the most lop-sided election victories.

The chances of Trump, with a 742 to 505 delegate lead over Cruz, winning the nomination on the first ballot are slim. It looks like he’ll fall short, given that he needs about 60 per cent of the remaining delegates and hasn’t won near that level in states so far.

"If he doesn't get it on the first ballot, it is going to be very difficult. The closer he gets to 1,200, the more likely he will win," said politics professor James Thurber at American University in Washington.

At that level, the battle will come down to trying to win over uncommitted delegates. This week Trump reshuffled his campaign team, assigning an expanded role to veteran political strategist Paul Manafort with the last of wooing unbound delegates.

Uncommitted delegates in Colorado, North Dakota and Wyoming and the far-off US territories of Guam, American Samoa and the US Virgin Islands, electoral orphans tied to no candidate at a convention and once considered irrelevant, may now decide the nomination.

Craig Shirley, author of Reagan's Revolution about the former president's 1976 campaign, recalled Ford winning over unbound delegates with rides in Air Force One, private meetings in the Oval Office, seats next to Queen Elizabeth at a White House state dinner and even a federal sewer contract for one delegate's hometown.

Explaining what might be in store for the Republican convention in Cleveland in July, Shirley said: "For a contested convention, think Goodfellas," referring to the famous Martin Scorsese mafia film.

Trump's golf courses in Florida, Ireland and elsewhere, and that "Trump Force One" aircraft of his could prove very useful this summer.