Complicating the equation for Democrats, presidential candidate John McCain clinched the Republican nomination on March 4. With Obama and Clinton engaged in the Democratic primary, McCain was free to define his candidacy for the general election largely unchallenged. Some Democrats expressed concern that Clinton stayed in the campaign through March and April, when they felt she had little chance to win the nomination, but a much greater chance to damage Obama's candidacy in the general election. However, others defended Clinton's right to continue on, arguing that a sustained campaign was good for the Democratic Party and that Clinton still had a realistic shot at the nomination.