His high-flying ambitions were widely reported to have included a possible vice-presidential bid as running mate to Democratic candidate Al Gore in this November's election.

But nothing much has gone right for Richardson this year as he tangled with hugely unpopular high gasoline prices and the failure to tighten security at the nation's top nuclear weapons laboratory at Los Alamos, in his home state.Although he was generally welcomed when he took over at Energy two years ago with a brief to tighten control over a wayward department, he has become a prime target for Republicans on the war path before the November elections.

Some demanded his head after two computer hard drives containing nuclear secrets disappeared from vaults at Los Alamos National Laboratory.The hard drives reappeared in the lab's secure X Division, but that only raised more questions about the possibility of espionage because the area had been searched twice before.

"It is extremely disturbing that the drives may have been surreptitiously placed back in the X Division," said Senate Intelligence Committee Chairman Richard Shelby. "We may have someone on the inside who doesn't want anyone to know they had the drives or what they did with them," the Alabama Republican said.

It was the second major security lapse at the lab to become public since Richardson was sworn in as the highest-ranking Hispanic in Clinton's administration in August 1998. Just seven months on the job, he was forced to deal with an explosion of criticism about lax security at the labs, which the Energy Department oversees, after accusations of Chinese espionage publicly erupted early last year.

Los Alamos scientist Wen Ho Lee was fired, and later charged with mishandling classified information by downloading classified material onto an unclassified computer. Lee is in jail awaiting trial and has pleaded not guilty.

That was then, this is now Richardson generally escaped blame at that time because he had been energy chief less than a year and security problems at the labs dated from much earlier.

Richardson's solution was to impose pages and pages of new measures to tighten security at the labs and appoint a security "czar" to take control of the situation.

After the hard drives disappeared, lawmakers on Capitol Hill were less forgiving, saying the blame lay squarely with Richardson because of his assurances that security had improved."Given the history of security and counterintelligence lapses at our national laboratories over the last few years, I am terribly upset that the attitudes toward security within DOE (Department of Energy) have not improved," said House Intelligence Committee Chairman Porter Goss.

"I hold Secretary Richardson responsible for these attitudes and practices," the Florida Republican said.