Tomorrow the balance of power in both houses of Congress is up for grabs, as is control of more than half of the nation's gubernatorial seats. Many of the races are still too close to call, and debates are raging about how the 2010 midterm elections will change the country. This is also the first election day you'll be able to follow in its entirety--via text and video--on Twitter.com.

We've rounded up some illuminating accounts and coverage below. But remember: none of this matters if you don't vote.

Parties and Candidates
Follow different sides of the conversation by checking out Twitter feeds from the Democrats (@thedemocrats), the Republicans (@gopconference), the Tea Party (@TPPatriots), and the Libertarians (@LPNational). @CSPAN has also compiled comprehensive lists of all the House, Senate and gubernatorial candidates on Twitter.

Election Coverage
Our @twittermedia team is working with top media outlets to integrate Tweets into their election coverage--and to bring that coverage onto Twitter.com.

When we launched Promoted Tweets in April, we outlined our plan for gradually rolling them out in all of the places people experience Twitter: first in search on Twitter.com, later in search through our partners, and eventually in the user timeline. We’ve accomplished the first two steps and, starting today, we are beginning to test syndication of Promoted Tweets in user timelines. Initially, we are testing these with our partner, HootSuite.

As we have done since the beginning of our Promoted product efforts, Twitter is taking a deliberate and thoughtful approach to this test. We’re carefully looking at how Twitter users react to and engage with Promoted Tweets in the timeline. We want to display Promoted Tweets in a way that’s both useful and authentic to the Twitter experience.

During this testing period with HootSuite, we will experiment with where and when Promoted Tweets are shown in the timeline. Not all HootSuite users will see Promoted Tweets and those who do may see different Promoted Tweets in different places in their timeline. As with Promoted Tweets in search, we will display Promoted Tweets in the timeline when they are relevant. Similar to our Promoted Account recommendations, we use several signals to determine a Promoted Tweet’s relevance to a user, including the public list of whom they follow. We will expand the rollout only when we feel we're delivering a high-quality user experience.

Since their introduction, users have engaged with Promoted Products on Twitter at rates that far exceed typical forms of online advertising. This next phase will bring Promoted Tweets to a wider audience and help even more people discover interesting accounts, people and information they may otherwise have missed.