With less than two months to go before the November 6 election, the focus of the media is on the presidential race. Power in Washington is perceived to reside in the White House and understandably so. However, power on the Potomac also splits between President Obama and a divided Congress. The House of Representatives is firmly in Republican control and they expect it to remain that way. The Senate has a 53-47 Democratic majority (with two of the 53 being Independents who caucus with the Democrats.) The November elections will not only tell us which party controls the White House. They will also determine if one party will once again control Congress and the White House. How key U.S. Senate races unfold will answer that question.

According to polling data compiled by realclearpolitics.com, Democrats currently are leading in 47 seats; Republicans in 46 and 7 are categorized as toss ups. It takes 51 votes to have a majority in the Senate. If President Obama is re-elected, the Democrats will need to hold on to their lead in their 47 seats and pick up three of the undecided ones, since Vice President Biden could then break any tie votes in the chamber. Republicans would need to hold on to their 47 seats and pick up four more if Obama wins a second term. If Romney wins, the GOP would need to hold what they now have and pick up a net of three more seats for control.

The best way for either party to advance their cause would be to pick up a seat currently held by the other party. That is likely to happen in three states: Nebraska, Wisconsin, and Maine. In Nebraska, Republican state senator Deb Fischer is an odds-on favorite to beat the Democrat, former U.S. senator Bob Kerry, in Democrat Ben Nelson’s open seat. In Maine, Republican senator Olympia Snowe is retiring and will likely be replaced by popular former governor Angus King, an Independent who would likely caucus with the Democrats. In Wisconsin, popular former GOP governor Tommy Thompson has a lead over Congresswoman Tammy Baldwin in Democratic senator Herb Kohl’s open seat.

The tosses up seats truly are toss-ups. In Indiana, Democratic Congressman Joe Donnely is running neck-and-neck with Republican state treasurer Richard Murdock in a state expected to go Republican in the presidential race. In North Dakota, another state expected to go for Romney, Republican Congressman Rick Berg has a slight lead over popular Democratic Attorney General Heidi Heitkamp. In Virginia, an open Democratic seat is too close to call as former Republican governor George Allen is in a dogfight with former Democratic governor Tim Kaine. Freshman Republican senator Scott Brown is in a toss-up race in Massachusetts over Democratic challenger Elizabeth Warren. In Montana, it is a flip of the coin between incumbent Democratic Senator John Tester and his challenger, Republican Congressman Denny Rehberg in a state that favors a Romney victory. Two states with Democratic incumbents on the ballot, Connecticut and Ohio, have recently switched from leaning Democrat to toss up and will likely stay that way until Election Day.

Today the battle for the senate likely stands at 47-47 with six true toss-ups. Perhaps the strongest factor in how those states turn in the senate elections will be which candidate for president carries them and delivers the momentum for his party in those races. It is definitely possible that when the sun rises on the morning of November 7, the split in the U.S. Senate will be 50-50 and the winning Vice-President will cast the deciding vote for who becomes President of the Senate and which party will control the committees and the agenda.