WASHINGTON — Sen. Barack Obama captured most of the delegates in Wisconsin and Hawai'i Tuesday, increasing his lead in the race for the Democratic nomination for president.

Sen. John McCain, meanwhile, moved closer to clinching the Republican nomination.

Obama won at least 55 delegates in the two states, with six still to be awarded. Sen. Hillary Rodham Clinton won at least 33.

In the overall race for the nomination, Obama led with 1,336 delegates, including separately chosen party and elected officials known as superdelegates. Clinton had 1,251.

Obama has built the lead by winning 10 straight contests since Super Tuesday. Among pledged delegates won in primaries and caucuses, Obama had a 155-delegate edge. Clinton has kept the overall race closer with more endorsements from superdelegates, who can support whomever they choose at the convention, regardless of what happens in the primaries.

It takes 2,025 delegates to secure the Democratic nomination.

On the Republican side, McCain won at least 34 delegates in Wisconsin and Washington state, with 22 delegates still to be awarded. Races in two Wisconsin congressional districts were too close to call Wednesday morning and complete results in Washington could take several days.

Overall, McCain had 942 delegates and former Arkansas Gov. Mike Huckabee had 245. It takes 1,191 delegates to claim the Republican nomination at this summer's national convention.

With Tuesday's results, Huckabee needs help from Mitt Romney's former delegates just to remain a viable candidate. Romney has withdrawn from the race and endorsed McCain. But the former Massachusetts governor has little authority over his 253 delegates, most of whom will be free agents at the convention in St. Paul, Minn.

The Associated Press tracks the delegate races by calculating the number of national convention delegates won by candidates in each presidential primary or caucus, based on state and national party rules, and by interviewing unpledged delegates to obtain their preferences.

Most primaries and some caucuses are binding, meaning delegates won by the candidates are pledged to support that candidate at the national conventions this summer.

Political parties in some states, however, use multi-step procedures to award national delegates. Typically, such states use local caucuses to elect delegates to state or congressional district conventions, where national delegates are selected. In these states, the AP uses the results from local caucuses to calculate the number of national delegates each candidate will win, if the candidate's level of support at the caucus doesn't change.