Although it emerged as a major grassroots movement in 2009, the Tea Party became a major force in American politics in 2010.

The full power of the Tea Party wasn't realized until Sept. 14, 2010, when Delaware Republican Christine O'Donnell defeated former governor and nine-term Congressman Mike Castle in the state's Senate primary election. Until that moment, the seven preceding Tea Party victories were viewed by mainstream Republicans as either happenstance, flukes or a weak Repubilcan field. Clearly, that was not the case in Delaware.

Although O'Donnell went on to lose to Democrat Chris Coons in the general election, O'Donnell's primary victory forced left-leaning pundits to grudgingly admit the legitimacy of the Tea Party as a force in American politics that was quickly growing influential. O'Donnell experienced a nine-point swing in pre-primary polling, which coincided directly with her late alliance with the Tea Party just two weeks before the election.

In Alaska, Tea Party candidate Joe Miller defeated one-term Sen. Lisa Murkowski in the GOP primary, but unlike Castle in Delaware, Murkowski mounted a write-in campaign and ultimately went on to defeat Miller in the general election.

Despite fielding many winning candidates in the general election, the outcome of the O'Donnell and Miller campaigns forced rank-and-file Republicans to question party leaders' commitment to the political process. In Delaware, the Republican party didn't get behind O'Donnell until just before the general election, leaving O'Donnell to fend for herself against scurrilous liberal attacks and underhanded whisper campaigns.

Had she received the full support of the GOP (which had backed Castle in the primary), O'Donnell staffers believed she would have won handily in November. Indeed, early pre-primary polling indicated she could have defeated Coons with the right message. In Alaska, the GOP made little effort to help Miller defeat Sen. Murkowski, who had been appointed to the seat by her father, Frank Murkowski, after he vacated it in 2002 to become governor. Without the state GOP's support, Murkowski went on to become the first woman in American history to win a write-in campaign in the general election.

As the Tea Party continues to gain power in 2011, most conservatives believe the mainstream GOP will be forced to embrace it. If not, party leaders may very well see a shakeup of revolutionary proportions.

In 2010, however, the growing influence of the Tea Party remains one of the top political stories of the year.