Two more retirements in the Senate this week altered the dynamics of the 2012 elections, as five Senate races next year will have no incumbent - and that number could still grow.

The latest Senator to decide against a re-election bid was Sen. John Kyl (R-AZ), a veteran member of both the House and Senate, who opted against a fourth term in the Senate.

Democrats have not won a Senate race in Arizona in 25 years - since 1986 - so this seat would likely start in the "Lean Republican" category.  Who might run for the Democrats?  As crazy as it might sound, the name of Rep. Gabby Giffords, who is still recovering from a gunshot wound to the head, was bandied around yesterday.

Along with Kyl's retirement this week, Democrats had one of their own decide to hang up his cleats, as Sen. Jim Webb of Virginia announced that he would not run for re-election, giving Republicans a big opening in their drive to win back the Senate.

"After much thought and consideration I have decided to return to the private sector, where I have spent most of my professional life," Webb said in a statement.

The Virginia Democrat had been all over the map during his time in the Senate, sometimes playing the role of more-moderate Blue Dog, and other times following the lead of liberal leaders in his party.

Along with Kyl and Web, other retiring Senators are Sen. Kent Conrad, a Democrat of North Dakota, Sen. Kay Bailey Hutchison, a Republican from Texas, and Sen. Joe Lieberman, an Independent from Connecticut who has sided with Democrats.

Republicans believe they have a great opportunity to win the Virginia seat, as well as the North Dakota seat being vacated by Conrad.

Lieberman's seat in Connecticut is expected to stay with Democrats, while the GOP would be favored in Texas and Arizona.

If Republicans were to pick up Virginia and North Dakota, they would be just two seats away from winning control of the Senate in 2012.

But, before we start awarding the next election to the GOP, I do have to remember the lesson that I learned in just the last few months.

If we rewind in our Senatorial Time Machine to two years ago, it was Democrats who were rubbing their hands together and giggling about the chances of winning well over 60 seats in the 2010 elections.

Back then, Republican Senators announced their retirement from Missouri and Ohio, and Democrats were thinking they had a great shot to win in New Hampshire and Florida.

But by the time the voters went to the polls in November of 2010, the Democrats weren't even close in Missouri, Ohio, Florida or New Hampshire, as the GOP held on to all of those seats.

Still, you can't ignore the signs right now that lean in the direction of Republicans.

But a lot of political water can still run under the 2010 election bridge.

Stay tuned.