Many in the GOP High Command are distraught that their party's frontrunner for the 2016 Presidential nomination, real estate magnate Donald Trump, will not agree emphatically to support the party's eventual nominee (should Trump himself not be nominated) and will not rule out waging a potential third party bid. Trump exclaimed in an August GOP Presidential debate: "Well I'm a natural negotiator and I like leverage, to be honest with you."
In American politics today, it is expected that all candidates for a party nomination support the eventual nominee, despite the enmity effectuated during the primary. This can be called the "Good Soldier Principle." In 1932, U.S. Senator James Reed (D-MO) was a vociferous supporter of Al Smith for the Democratic Party nomination. Smith had won the nomination in 1928 but lost the General Election to Republican Herbert Hoover. Reed came to despise one of Smith's Democratic opponents, Franklin D. Roosevelt. When Roosevelt mustered the nomination, Reed did not want to address the party's convention to offer his support for Roosevelt. However, a Roosevelt advisor, Arthur Mullen, appealed to Reed's sense of party unity, reminding him: "We're all Democrats, Jim." Reed then sauntered to the podium and told the convention delegates: "At a time like this, every man who claims to be a Democrat should banish from his heart all feelings of disappointment, all sense of chagrin, and like a good soldier, fall in line, salute the colors and face the enemy."
Contrariwise, John F. Kennedy averred: "sometimes, party loyalty asks too much." American political history is flush with examples of elected officials and former elected officials who did not support their party's nominee in the Presidential election, and some even actively campaigned for an opponent or even ran as a third party candidate in the General Election.
Ironically, Al Smith, unlike James Reed. was not a good soldier after Roosevelt was elected President. Smith was a conservative Democrat who believed the federal government should be a limited purpose entity which only acts under narrowly defined situations. He came to see Roosevelt's "New Deal" as too pervasive. Smith lambasted Roosevelt for pitting "class against class." Smith even actively campaigned for Roosevelt's Republican opponents in 1936, and again in 1940, Alf Landon and Wendell Willkie, respectively.
Smith became persona non grata in many Democratic circles, and some Democratic loyalists branded his actions "treason." When Smith announced he would support Landon over Roosevelt in 1936 the President employed Smith's 1928 Vice Presidential runningmate, U.S. Senator Joseph Robinson (D-AR), to brand Smith derisively as "The unhappy warrior." Roosevelt have given Smith the moniker "happy warrior" when the two Democrats ware allies. It was meant as a term of endearment.
In 1896, with the country mired in an economic recession, the Democratic Party, which was known as the conservative party of the time, nominated the fiery populist William Jennings Bryan for President. The incumbent President, conservative Democrat Grover Cleveland, who was not seeking renomination, was appalled. The Bryan nomination was a repudiation of Cleveland's policies of fiscal austerity and the continuation of the Gold Standard. Bryan favored dramatic action by the federal government to stimulate the nation's economy, and favored the U.S. leaving the gold standard and instituting a graduated federal income tax.
Cleveland was not a good soldier. He refused to "fall in line" and pledge allegiance to Bryan. Instead, he lent his support to John A. Palmer, the nominee of the small National Democratic Party. Palmer was more in line with Cleveland's conservative ideology. Palmer pocketed less than 1% of the vote. Republican William McKinley handily won the election.
In 1912, former progressive Republican President Theodore Roosevelt became disillusioned by the actions of his handpicked Republican successor William Howard Taft. He came to view Taft as too conservative and too close to business interests. Accordingly, Roosevelt launched a bid against Taft for the Republican Presidential nomination. He told news reporters: "My hat's in the ring. The fight is on, and I'm stripped to the buff." Like Trump, Roosevelt was not above ad homonym attacks on his political opponents. He quipped that Taft is: "dumber than a guinea pig, a fathead."
After Roosevelt was embarrassed during the GOP primaries, losing his home state to Taft, Roosevelt announced that if he lost the nomination, he would run for President as an Independent. After that announcement, Roosevelt won a string of Republican primary victories. He won 284 delegates in the primaries, compared to just 125 for Taft. However, Taft secured the nomination because of his support of "pledged delegates" (individual Republicans who had a vote at the convention). In addition, Roosevelt forces alleged the convention was rigged for Taft by the President and GOP Chairman Elihu Root. True to his word, Roosevelt bolted the Republican Party and ran as the nominee of the Progressive, a.k.a. Bull Moose Party. In the General Election, the Republican Party was split asunder; Progressives voted for Roosevelt and conservatives marked ballots for Taft. Democrat Woodrow Wilson won the election.
This schism between the conservative and progressive bloodlines in the GOP evinced itself again in 1924. Progressive Republicans became disillusioned with the conservative policies of Republican President Calvin Coolidge. Twelve maverick GOP U.S. House members supported the candidacy of the Progressive Party nominee, U.S. Senator Robert La Follete Sr. (R-WI). U.S. House Speaker Nicolas Longworth (R-OH) showed no mercy, making sure mutineers did not serve on important committees during the next Congressional session. In the U.S. Senate, La Follete Sr., and three of his Republican colleagues who had supported his candidacy, lost all of their committee assignments.
Once a politician egresses political stage left, he/she has the liberty to support a candidate of the opposing party without the fear of losing the party's support when up for re-election, losing a coveted committee assignment.
In 1968, U.S. Senator Eugene McCarthy (D-MN), whose flagship issue was ending U.S. involvement in the Vietnam War, lost the Democratic Presidential nomination to Vice President Hubert Humphrey. Humphrey had supported the policies of President Lyndon B. Johnson of continuing the war. In part because of the influence of McCarthy and his vociferous supporters, on September 31st, Humphrey announced that as President he would order a unilateral bombing halt in Vietnam "as an acceptable risk for peace."
Even after that concession, McCarthy did not play the role of a good soldier and publically support Humphrey. In fact, McCarthy did not formally endorse Humphrey until a week before the General Election. His endorsement finally came as Humphrey, once far behind in the polls, had rallied to being within just two points of Republican nominee Richard M. Nixon. McCarthy's endorsement was less than enthusiastic. He proclaimed to his supporters: "I'm voting for Humphrey, and I think you should suffer with me." McCarthy's late and tepid endorsement was blamed by some Democrats for Humphrey's whisker-close loss to Nixon.
Trump is proving that he is not a "good soldier" for the Republican Party. Ironically, This may actually help him with grassroots conservatives and Independent voters who themselves are conservatives first and Republicans second. It also continues to cause trepidation among Republican stalwarts that he could split the conservative vote in the General Election, ensuring a Democratic victory. As a savvy business magnate, Trump is playing the "leverage card" well.