The primary contest began with a fairly wide field, as the Republicans lacked an incumbent President or Vice President. Texas Governor George W. Bush, son of George H. W. Bush, the most recent Republican president, took an early lead with the support of much of the party establishment and a strong fund-raising effort. Former cabinet member George Shultz played an important early role in securing establishment Republican support for Bush. In April 1998, he invited Bush to discuss policy issues with experts including Michael Boskin, John Taylor, and Condoleezza Rice. The group, which was "looking for a candidate for 2000 with good political instincts, someone they could work with," was impressed, and Shultz encouraged him to enter the race.
The main primary season, then, came down to a race between Bush and McCain. McCain's campaign, centered on campaign finance reform, drew the most press coverage and the greatest popular excitement. Many Republicans complained that Democrats and other non-Republicans enrolled in the party for the express purpose of voting for McCain, thus skewing the results. Bush's campaign focused on "compassionate conservatism," including a greater role for the federal government in funding education and large reductions in the income and capital gains tax rates.
In the South Carolina primary, McCain's momentum was halted by a strongly negative Bush campaign. Although the Bush campaign said it was not behind any attacks (more on this below), locals who supported Bush reportedly handed out fliers and made telephone calls to prospective voters suggesting among other things, that McCain was a "Manchurian candidate" and that he had fathered a child out of wedlock with a black New York-based prostitute (an incorrect reference to a child he and his wife had adopted from Bangladesh). McCain won primaries in Michigan, his home state of Arizona, and a handful of Northeastern states, but faced difficulty in appealing to conservative Republican primary voters in spite of demonstrated support from Democrats and independents. Bush's victories in states like California and New York as well as conservative Southern states gained him the nomination long before the Republican Convention.
Allegations were made that Karl Rove was responsible for a South Carolina push poll that used racist innuendo intended to undermine support for McCain: "Would you be more likely or less likely to vote for John McCain for president if you knew he had fathered an illegitimate black child?" McCain campaign manager Richard Davis said he "had no idea who had made those calls, who paid for them, or how many were made," but in the 2004 film Bush's Brain, John Weaver, political director for McCain's 2000 campaign bid, stated, "I believe I know where that decision was made; it was at the top of the Bush campaign." Rove has continually denied any such involvement. The existence of such a poll is disputed since no recording of the poll has ever been documented (about 20% of robocalls are usually recorded by answering machines). The only person who claimed to hear about the push poll was a teenager who asked John McCain about it at a townhall meeting.
Other candidates included social conservative activist Gary Bauer, businessman Steve Forbes, Utah Senator Orrin Hatch, former AmbassadorAlan Keyes, former Tennessee Governor Lamar Alexander, former Red Cross director and cabinet member Elizabeth Dole, Ohio Congressman John Kasich, and former Vice President Dan Quayle. Bauer and Hatch campaigned on a traditional Republican platform of opposition to legalized abortion and reductions in taxes. Keyes had a far more conservative platform, calling for the elimination of all federal taxes except tariffs. Keyes also called for a return to a ban on homosexuals in the military, while most GOP candidates supported the "don't ask, don't tell" policy. Keyes continued to participate in the campaign for nearly all the primaries and continued to appear in the debates with frontrunners McCain and Bush. As in 1996, Forbes campaigned on making the federal income tax non-graduated, an idea he called the flat tax, although he increased his focus on social conservatives in 2000. Although Forbes came a close second to Bush in the Iowa caucuses and tied with him in the Alaska caucuses, none of these other candidates won a primary.