Texas, which leads the nation in capital punishment, is scheduled to execute two convicted murderers Wednesday night. One of them may be mentally retarded, officials said today.

The executions could present another death penalty controversy for Texas Gov. George W. Bush, the Republican presidential nominee who is running as a "compassionate conservative" but has faced repeated criticism for his home state's many executions.

Unless the courts or Bush himself intervene, Brian Roberson, 36, and Oliver Cruz, 33, are set to die by lethal injection in consecutive executions at the state prison in Huntsville, Tex.

"We think it's a go for both of them," said Texas Department of Criminal Justice spokesman Larry Todd. "We're preparing as we do for any execution."

Even in Texas, multiple executions are rare and the question of whether mentally retarded people should be put to death has been discussed in the Texas Legislature. Thirteen states prohibit executing the retarded.

Texas has executed 225 people since resuming capital punishment in 1982 after a national death penalty ban was lifted, but only twice in that time have two people been put to death on the same day.

Two other states, Illinois and Arkansas, have performed multiple executions on one day during the same period.

Roberson was sentenced to die for the 1986 murder of two people during a Dallas burglary and Cruz for the rape and murder of a woman in San Antonio in 1988.

Their execution dates, set by separate judges, are on the same day only by happenstance, Todd said.

Both men have appealed to the Supreme Court to stop their executions and have requested clemency from the Texas Board of Pardons and Paroles, said Heather Browne, spokeswoman for Texas Attorney General John Cornyn.

Cruz's attorney, Jeffrey Pokorak, said his client is mentally retarded because he scored less than 70 on an IQ test.

He said he hopes to delay Cruz's execution because he has been told by members of the Texas Legislature that they are likely to pass legislation next year banning the execution of retarded people.

"That's the terrible tragedy of this case. The law is going to prevent the execution of people like Cruz in six to eight months, so he would be the last retarded person to die under the old law," Pokorak said.

Last year, the legislature turned down a similar proposal. Bush took no stand on the issue but is satisfied that "current Texas law already contains protections to make sure that a person who's mentally incompetent isn't executed," said Bush spokesman Mike Jones.

Bush could grant a 30-day reprieve in both cases, but Jones said he would not take action until all legal appeals had been exhausted.

Bush has granted only one temporary reprieve, which came on June 1 when he gave convicted murderer Ricky McGinn a stay so DNA tests could be performed.

Since Bush took office in 1995, 138 people have been executed in Texas, the most recent on July 26.

In June, Bush came under political fire for the execution of Gary Graham, who was put to death amid doubts by some critics about his guilt in a 1981 murder.

Bush did not intervene in the case, saying he believed Graham was guilty.

Should both executions go forward Wednesday, Todd said they would be performed one after another about an hour apart, with Roberson going into the death chamber first because prison officials received his execution order first.