(CNSNews.com) - Sen. James Jeffords has called a 9:30 a.m. press conference in Vermont, and he's widely expected to announce he's leaving the Republican Party to become an independent - one who will organize with the Democrats.

As power in the Senate shifts to Democrats for the first time since 1994, some Democrats and liberal media pundits are blaming the Bush administration for "bullying" Jeffords into making the jump.

They note that President Bush didn't invite Jeffords to a White House reception honoring the national teacher of the year - a Vermonter. That's considered the "minor slight."

In addition, although President Bush never said so, published reports suggested his administration might retaliate against Jeffords by seeking changes in a dairy program that benefits farmers in Vermont and the Northeast. Republicans were angry because Jeffords had opposed President Bush's tax-cutting plan as too big and too much of a threat to the education spending he favors.

While some examine what's making Jim Jeffords jump, others are focusing on changes in committee chairmanships - and what that means for Bush's legislative agenda.

In a nutshell, Democrats say, the shift in Senate power will force the Bush administration to be less conservative than it set out to be.

With Democrats at the helm, Bush's judicial appointments and legislative priorities - including oil exploration -- may take a back seat to more liberal concerns - including prescription drug benefits, more school spending and environmental protections.

Gloomy Republicans attempting to look on the bright side include Sen. Richard Shelby of Alabama, who jumped from the Democratic Party to the GOP some years back. On Wednesday, he told reporters that Jefford's defection might "galvanize" Republicans. "This might help us in a year and a half," he said, referring to the midterm election.

Some pundits are mulling the possibility that Sen. Trent Lott (R-Miss.) - the current majority leader - may not become minority leader in the newly reconfigured Senate. Some speculate that other Republicans, unhappy with Lott's leadership, may challenge him for the minority leader post.

Newspaper editorials

Leading newspapers weighed in Thursday on Jeffords' expected party switch. The New York Times, calling Jeffords' anticipated announcement "a dramatic transformation of the political landscape," noted that he "has single-handedly redrawn the legislative map on Capitol Hill."

The Times editorial said Jeffords has given President Bush and "his suddenly clumsy-looking operatives an embarrassing lesson on how not to take someone for granted."

The newspaper compared Jeffords to Ronald Reagan, who - when he switched to the GOP in the 1940's - said he had not deserted the Democratic Party, but that the Democratic Party had deserted him. "That is precisely what happened to Mr. Jeffords," said the newspaper.

The editorial concludes that Jeffords' defection "ought to provide a sobering lesson to the White House - that Bush and Cheney's "complacency, followed by ham-handed snubs and pressure tactics, are going to have to be reassessed at the highest level...Mr. Bush may now have to use more consistently the bipartisan tactics he espoused in the campaign."

The Washington Post said the biggest impact of Jeffords' defection may have more to do with the judiciary than it does with legislation. "Conservative nominees - a string of them anyway - could be expected to have a harder time."

The editorial said the shift in Senate power also makes it more likely that President Bush will have to choose between signing a "serious" campaign-finance reform bill - or vetoing it.

The Washington Post opines that Jeffords "plainly felt isolated" by President Bush's conservative policies, and "the GOP may be about to pay a price for that." The two lessons, the newspaper said, are this: The Republican Party should be more accommodating to moderate views, or it should be even more tightly disciplined than it has been. "It will be interesting to see which way it leans," the editorial concludes.