Moments after Sen. John Kerry (D-Mass.) voted to extend the ban on assault weapons Tuesday, he was ushered out of the chamber by Sen. Edward Kennedy (D-Mass.) for a staged photo opportunity with three of his colleagues.

As flash bulbs illuminated the dimly lit hallway outside of Senate Minority Leader Tom Daschle’s (D-S.D.) office, it was apparent that even before Super Tuesday was halfway over, Kerry had become his party’s presidential nominee.

Suddenly it became clear that the presidential campaign at times will be rolling through the corridors of the Capitol — in addition to playing out in key battleground states across the nation.

Almost as if it were on cue, House Republican leaders quickly issued word that they’re planning a news conference today at Republican National Committee headquarters in which they will blast Kerry on fiscal issues, including his alleged support for “big government, tax hikes and deficits.”

And Senate Republicans emerged from their weekly strategy meeting Tuesday condemning the Massachusetts Democrat for missing votes and suggesting that he had come to the Capitol only to stage a political stunt around the gun liability bill, which ultimately went down to defeat anyway.

“Isn’t this the first vote of 2004?” Sen. Conrad Burns (R-Mont.) asked of Kerry’s poor attendance record. “He wasn’t here on some really important votes and the one he shows up on is the one that is going to put gun manufacturers out of business. My gosh, give me a break.”

In addition to voting to extend the assault weapons ban for another 10 years, Kerry also voted to close the so-called gun show loophole that would require people who purchase firearms at gun shows to undergo background checks. It was the first two votes he cast this year.

That enabled Democrats to score two big wins. But it may have been hollow victories because the National Rifle Association, realizing it had suffered major defeats on the amendments, quickly urged Republican Senators to vote the underlying bill down — which they accomplished in order to wipe out the entire legislation.

Even before the Super Tuesday votes were counted last night, the election had shifted for Kerry supporters from a raucous primary contest to a straight-forward general election battle against President Bush.

“I believe he is” the nominee, Sen. Dianne Feinstein (D-Calif.) said. “I think it is impossible to overturn the lead he has.”

Kerry overshadowed his chief rival for the nomination, Sen. John Edwards (D-N.C.), who also returned to Capitol Hill to vote for the gun amendments.

While Edwards was still en route to Capitol Hill for the votes, Kerry was already on the Senate floor offering the final word for his party on assault weapons in a politically-laced floor speech where he questioned Bush’s position on gun control and other domestic issues.

“When he ran for president in 2000, President Bush promised the American people that he would work to renew the assault weapons ban,” Kerry charged in a speech carried live by the 24-hour news networks. “But now, under pressure, he is walking away from that commitment as he has from so many other promises from education to the environment to the economy.”

Only a handful of Senators were actually on the floor during Kerry’s remarks including Sen. Mike Enzi (R-Wyo.), the presiding officer, who appeared more interested in reading several memos and letters he had brought with him to review while sitting in the chair.

“I thought it was nice he could come back for a day of voting,” Enzi cracked.

As for the content of Kerry’s remarks, “There wasn’t anything unexpected in his speech,” the Wyoming Republican added.

Senate Republican leaders said they were not surprised that Kerry used his opportunity on the Senate floor as a soapbox to try to draw a sharp contrast with Bush’s vision for the country.

“The Senate floor is used all the time to push agendas of all sorts and the fact there would be a presidential candidate making politically-charged speeches on the floor of the Senate is not terribly shocking to me,” said Senate Majority Whip Mitch McConnell (R-Ky.).

And McConnell noted that Democrats would not be the only Senators using the floor to promote their respective legislative agendas in the months leading up to the November elections.

“We are going to be talking about the legislation that is before us in the Senate and in a presidential year it all has political implications,” the Kentucky Republican added.

For his part, Kerry said he would return to the Senate throughout the year if circumstances warrant it.

“It depends on the votes,” Kerry said as he walked through the Capitol. “I have said if it is a close vote and a critical issue obviously I want to try to be here.”

In the coming weeks and months, one of Kerry’s tasks will be to convince his Senate and House colleagues to rally around his campaign and in doing so help him set up critical political operations in all 50 states.

“We are going to be building a strong grassroots effort nationally as we can,” he vowed.

The return of Kerry and Edwards was reminiscent of Vice President Al Gore’s February 2000 visit to the Capitol, when he made a quick decision to leave the campaign trail in New York to be on hand to break a tie on an amendment that was important to abortion rights supporters. While Gore never had to cast the vote, he used the opportunity to hold a news conference with prominent Democrats.

Unlike Gore, who sat in the chair as the Senate’s presiding officer on that February day, both Edwards and Kerry stood on the floor talking to their former colleagues and at times were standing together as Senators streamed into the chamber to cast their votes.

Kerry would not disclose what he said to his rival other than, “We chatted and had a good conversation.”

Edwards chose to keep a lower profile saying he simply enjoyed seeing his colleagues. The Democratic and Republican Senators, who talked with the two contenders during the votes, were equally coy about their conversations.

Sen. Kent Conrad (D-N.D.) acknowledged there was “a little” talk about the campaign, but he said the private conversations were focused “more on personal stuff.”

“It was very relaxed, a lot of humor,” Conrad said. “I think they both feel very good about how they have done and there was a kind of quiet confidence both of them had.”

Sen. John McCain (R-Ariz.), who sought the GOP presidential nomination in 2000, said he spoke to Kerry about the daily grind of the campaign schedule.

“We talked about the fact that you have to take this disinfectant for your hands because it is so easy to catch colds,” a smiling McCain said, adding: “We talked about getting rest.”