Texas's Republican Lieutenant Gov. Dave Dewhurst officially jumped into the race to replace retiring Sen. Kay Bailey Hutchison (R), tellng supporters in an emailed video message that he would be "unapologetically conservative and as serious as the problems we're currently facing," according to The Associated Press.

Dewhurst starts out as the front-runner in the race: He is the best-known candidate around the state. He's also a millionaire who plans to spend much of his own money on the race.

But he has a primary fight on his hands. Former Texas Solicitor General Ted CruzRafael (Ted) Edward CruzCruz's Dem challenger slams Time piece praising Trump Race for Republican Speaker rare chance to unify party for election 32 male senators back Senate women's calls to change harassment rules MORE is campaigning on a Tea Party platform and has been endorsed by conservative favorite Sen. Jim DeMint (R-S.C.), whose Senate Conservatives Fund might spend millions helping Cruz. He also has the backing of FreedomWorks, a deep-pocketed national Tea Party group.

Former Dallas Mayor Tom Leppert is also in the race. He is known more as a business conservative with a more centrist record on environmental and labor issues, which could hurt him with the very conservative primary base. But if Dewhurst and Cruz veer hard right in the primary fight, there could be room for him to emerge as a contender.

Democrats hope to contest the seat, and think they have a top recruit in Former Army Lt. Gen. Ricardo Sanchez. While they have had little success in statewide races in Texas in the last two decades, the Lone Star State's shifting demographics might soon make the state competitive. Texas is now majority-minority, and while some Hispanics are not citizens and both the Latino and African-American populations have higher proportions of people not yet at voting age, the groups are becoming a bigger factor in the state's politics.