Grateful that a Senate holdout no longer opposed his nomination, U.N. Ambassador John Bolton said Sunday the turnabout represented "a fairly dramatic change in the political dynamic."

"I think the main thing is allowing the nomination to come to a vote on the floor of the Senate, and then people can vote how they wish," Bolton said.

"The problem last year, of course, was we couldn't get a vote at all. I'm hoping we can avoid that this time and let there be a vote on the floor," he said.

The GOP-controlled Senate Foreign Relations Committee has scheduled a hearing Thursday on Bolton's nomination.

Sen. George Voinovich, R-Ohio, frustrated his GOP colleagues last year when he opposed Bolton in the committee. That led President Bush to install Bolton through a temporary appointment that expires in January.

But the senator has had a change of heart, saying last week that he would not block Bolton's nomination this year because of an urgent need to ease tensions in the Middle East.

Voinovich said pressing diplomatic issues with Iran, North Korea and in the Middle East require a smooth approval process for the man he once called a bully.

"Obviously, I much appreciated it, and I think it represents a fairly dramatic change in the political dynamic in the Senate," Bolton said.

"All of the Republicans, I think, are now supportive, and I think a number of Democrats will be as well. So we'll do this one step at a time, have a hearing this coming Thursday and see what happens after that," he said.

But a Democrat on the committee, Sen. Christopher Dodd of Connecticut, said he expected "this is going to be a bruising fight. I regret this. I'm sorry the administration wants to go forward with this. The problems still persist."

During the contentious confirmation process, Democrats accused him of mistreating subordinates and intimidating intelligence analysts who didn't support his hawkish ideology. Investigations ended with no proof of improper actions.

Voinovich said that his observations are that "while Bolton is not perfect, he has demonstrated his ability, especially in recent months, to work with others and follow the president's lead by working multilaterally."

Bolton appeared Sunday on "FOX News Sunday" and another cable news network.