Florida voters go to the polls today to choose nominees in House and Senate races.

The top primaries to watch tonight include the 7th district, where Republican Reps. Sandy Adams and John Mica face off; the 9th district, where former Rep. Alan Grayson (D) and his allies have put money behind pushing voters toward a GOP nominee who will be less competitive in the general election; and the 26th district, where Democrats will choose their nominee to take on vulnerable Rep. David Rivera (R).

Polls are open from 7 a.m. to 7 p.m. today.

Senate

Rep. Connie Mack IV (R) is not among the most impressive Senate candidates, but given that all his serious primary opponents have dropped out, he should post an impressive win today. The long shots are former Rep. Dave Weldon, retired Army Col. Mike McCalister and activist Marielena Stuart. How much beyond 50 percent of the vote Mack garners could prove instructive heading into the November matchup against Sen. Bill Nelson (D). The two-term Senator also faces a nominal challenge from one candidate.

House

2nd District

National Democrats had big hopes for folksy farmer and state Rep. Leonard Bembry, believing he could take out freshman Rep. Steve Southerland (R). Now Bembry, who was endorsed by the conservative Democratic Blue Dog PAC, looks very likely to lose the Democratic primary against affable former state Sen. Al Lawson. Though he represented most of the counties in the district during his state legislative career, Lawson would be a considerable underdog to win the district. His victory could well take the seat out of play for November.

6th District

The winner of the GOP primary is almost certain to be the new Congressman from this comfortably Republican coastal district. And, during the past weeks, it’s appeared more and more likely that the GOP nominee will be Ron DeSantis, a retired Navy JAG officer and current Navy reservist. DeSantis, an impressive fundraiser who has racked up a series of potent conservative endorsements, faces six primary opponents. They include former Ruth’s Chris CEO Craig Miller, Jacksonville City Councilman Richard Clark and state Rep. Fred Costello. DeSantis aides are cautiously optimistic about tonight’s results, having seen consistent polling with their candidate well ahead of his competitors.

7th District

Rep. John Mica, chairman of the powerful Transportation and Infrastructure Committee, appears poised to beat tea-party-affiliated freshman Rep. Sandy Adams in what is perhaps today’s most-watched primary.

Adams, who has racked up impressive endorsements from the likes of former Alaska Gov. Sarah Palin (R) and former Secretary of State Condoleezza Rice, never managed to put together the necessary ground game to beat a much better-financed opponent, GOP operatives in the state said. Though she had some significant support from the conservative grass roots, the outside spending that she would have needed to approach financial parity with Mica never arrived. Mica, quite conservative himself, began the race with very high name identification and appears likely to win comfortably.

9th District

Former Rep. Alan Grayson (D) and his allies have worked hard to ensure he faces an opponent other than Osceola County Commissioner John “Q” Quiñones, seen by both Democrats and Republicans as the strongest potential GOP general election candidate. The pro-Democratic House Majority PAC has spent about $81,000 encouraging GOP primary voters to choose a candidate other than Quinones. And the Grayson campaign has spent an as-yet-undisclosed amount in a similar effort.

Grayson is favored in the Democratic-leaning district no matter who the Republican candidate is, but Republicans think this could be a real race if Quiñones is the nominee. He faces attorney Todd Long, veteran Julius Melendez and businessman Mark Oxner. Long appears to have the momentum behind him, but this race is one to watch closely.

19th District

This strongly Republican district, left open by the decision of Rep. Connie Mack IV (R) to run for Senate, will elect a Republican to the 113th Congress. Who that will be is decided today in a fight among six candidates. The leading contenders are state Rep. Paige Kreegel and radio talk-show host Trey Radel. Also running are state Rep. Gary Aubuchon and former Capitol Hill aide Chauncey Goss.

“It’s really a dogfight for Reidel and Kriegel, and I just don’t see that Goss has the resources to do much,” explained a Florida GOP operative involved in the race. That’s probably about right. Recent public polling indicated Goss, endorsed by former boss Rep. Paul Ryan (R-Wis.), is in a battle with Aubuchon to finish third.

26th District

Who will take on embattled and vulnerable GOP Rep. David Rivera? That’s the question facing Democrats today in the southern Florida district that stretches as far south as Key West. And the answer appears more likely than not to be former Miami-Dade Democratic Party Chairman Joe Garcia.

This is Garcia’s third campaign for Congress in South Florida. He lost to Rivera in 2010 by more than 9 points. In 2008, Garcia lost to Rep. Mario Diaz-Balart (R) by just more than 6 points. But if he wins the primary today, he’ll have a shot at the seat. His opponent in today’s race is businessman woman Gloria Romero-Roses, who has the tacit support of the Florida Democratic Party.

Party operatives believe Romero-Roses would make a much stronger candidate against Rivera and are less likely to play in the race if she isn’t the nominee. Romero-Roses has run a good campaign, but Garcia definitely has the edge in today’s race. His aides are cautiously optimistic, having consulted internal tracking polls.