As the Republican presidential nominating contest appears to start winding down, Senate races across the country are just starting to heat up. And there's a lot at stake for both parties. Democrats are attempting to hold on to a slim 53-47 majority in the chamber (including Independents), while Republicans are seeking to seize on what looks like a pretty sizable advantage. Come November, Democrats will be defending 23 Senate seats, including six open seats; Republicans will only have to defend ten. Even so, right now it's impossible to tell which way the wind will blow.
In the following slides, CBS News presents -- in no particular order -- the top ten Senate races to watch going into the 2012 elections.