It's like the first day of school in the Senate. Freshman, nine of them new to Washington, running around looking lost, wandering into the wrong rooms, forgoing their restroom needs during hours-long orientation sessions, paperwork, speeches from current members, discombobulated spouses, and on and on.

It's a big day for Republicans, as GOP Leader Mitch McConnell, R-Ky., welcomed 16 new GOP colleagues to his office on Monday morning, this after the minority party flipped six previously-Democratic seats on November 2.

Beaming from ear to ear, McConnell proclaimed to the on-looking television cameras, "Obviously, I'm pretty excited to be sitting here...This is going to be a huge improvement for the United States Senate from our point of view, and I believe the American people sure have chosen outstanding members to join the United States Senate."

Still, it was not a big day for everyone. It's often a difficult time when vanquished incumbents must return to perform humbling tasks. Sen. Bob Bennett, R-Utah, ousted in a GOP primary by former Supreme Court Justice Samuel Alito's clerk, Mike Lee, is top Republican on the Rules Committee, which controls office space and budgets. Bennett gave a speech to the new members, including his former opponent, about hiring competant staff, but he told reporters afterward that he also injected a poignant piece of advice.

"I told them that regardless of your partisan position, recognize that the senators with whom you deal are not caricatures. They are real people. So, whether you are a Republican or Democrat, you are dealing with human beings. Make friends across the aisle, across ideological barriers," Bennett exhorted the freshmen.

Just down the hall, a more sedate affair in the office of Democratic Leader Harry Reid, a closed-door meeting with his two new members, Senators-elect Joe Manchin of West Virginia and Delaware's Chris Coons, out of the view of cameras.

And it was baptism by fire for those two men, as the midterm elections in their states also served as special elections to replace vacant positions. Both are legislating right away in the current lame duck session.

At 4:00pm Eastern, the former Mountain State governor and New Castle County executive will be officially sworn in by Vice President Joe Biden, who doubles as the President of the Senate, a somewhat emotional moment for the former senior senator from Delaware whose son, Beau, was long thought to be his father's heir apparent. The younger Biden chose to remain the state's attorney general, because, some experts said, he feared he would not win against the presumptive GOP challenger, Rep. Mike Castle. But Castle, a popular former governor, was surprisingly ousted in the state's closed primary by Tea Party upstart Christine O'Donnell.

Manchin, according to a spokeswoman, will not only carry his family Bible, often a Senate tradition for members as they are sworn in, but also a reminder of the historic figure he is replacing. The late Sen. Robert Byrd, D-WV, the longest serving senator in history, gave the former governor a copy of the Constitution before he died, and Manchin plans to have that document with him when he takes the oath of office Monday afternoon.