In recent elections, there have been no more reliably Democratic constituencies than minority voters. African Americans backed Al Gore 9 to 1 in 2000, Hispanics supported him 2 to 1 and Asian Americans voted for him 4 to 3.

Such support has been accompanied by rising political aspirations among those groups. But those aspirations haven’t always been satisfied, and with that have come growing frustration and some tension.

Despite a growing number of African Americans, Hispanics and Asian Americans in Congress, legislatures and local offices, few have reached the major statewide offices, let alone national office.

Only two African Americans have been elected to the Senate, and only one as a governor. None serves in either post now.

Likewise, there are no Hispanic senators or governors. Most elected in past years have come from New Mexico, which is more than 40 percent Hispanic.

Most Asian American governors and senators have come from Hawaii.

This year, significant minority candidates are seeking top offices in Texas, Illinois and New York. That could produce either a breakthrough or more frustration, and it could test whether minority candidates can get enough white votes to win major statewide elections.

In Texas, the top Democratic gubernatorial candidates are Hispanic, Tony Sanchez and Dan Morales. The party’s Senate field is headed by Victor Morales, who is Hispanic; Ron Kirk, an African American; and Ken Bentsen, who is white.

Polls show that Sanchez and Morales are underdogs to Republican Gov. Rick Perry. A recent survey by The Dallas Morning News showed that the Senate race was more competitive, with no statistical difference in the way Republican John Cornyn matched up with each of the three Democrats.

Many top Democratic leaders have endorsed Kirk, in part because they feel that a tandem of the former Dallas mayor and a Hispanic gubernatorial nominee might boost the entire ticket in a state where the electorate is at least one-fourth Hispanic and African-American.

In Illinois and New York, meanwhile, Democrats may have their first African-American gubernatorial nominees.

In Illnois, former state Comptroller Roland Burris, a veteran officeholder and candidate, is in a close race with two major white rivals in next month’s primary.

And in New York, state Comptroller Carl McCall is pitted against Andrew Cuomo, the former secretary of housing and urban development and the son of former Democratic Gov. Mario Cuomo. Polls show a close contest for September’s primary, with both candidates trailing Republican Gov. George Pataki.

One potential factor in all three states is that minorities form a larger proportion of the Democratic primary electorate than of the general election total.

To the extent that voters vote along racial lines, that would give an African-American a better chance in a primary than in a general election. That, in turn, could present a dilemma to primary voters seeking a nominee with the best chance to win.

It also could pose a general-election problem for the Democrats if they pick a minority nominee who might lose some white votes or a white nominee who could suffer from resentment by minority voters.

Racial divisions may have cost the Democrats last year’s race for New York mayor. A bitter Democratic primary in which Mark Green, who is white, defeated Fernando Ferrer, who is Hispanic, led many Hispanics to back Republican Michael Bloomberg, who won narrowly.