We just added two new races to the site: In Montana, Jon Tester is facing off against Denny Rehberg, while in Massachusetts, Scott Brown is trying to fend off Elizabeth Warren. Dig in and start reading.

Also updated are the polling numbers for the previous races. The Democrats have fared well in the past couple weeks: In the presidential race, Barack Obama opened up nearly a 4-point lead over Mitt Romney. In the hotly contested Senate races, meanwhile, Tim Kaine moved from a tie to a 4-point lead over George Allen, and Claire McCaskill maintained her edge over Todd Akin.

Finally, we added a new feature called “The Grid” to the Obama-Romney race. It shows each of the candidates’ stances on 10 of the most important issues, from abortion to the deficit and climate change to health care, in an easy-to-compare chart. Check it out.