The Wolverine State lives up to its tradition of feisty primaries today with an important Senate contest and several House races to watch.

The races echo prevalent themes in GOP primary battles throughout the country: the proliferation of third-party spending, upstart tea party challengers and incumbency as both a pro and a con. Additionally, the politics of race and the state’s devastated economy loom large in two House districts around downtown Detroit.

Republicans controlled the redraw of the Congressional map in Michigan, which lost a House seat because of reapportionment. The GOP used the power of the pen to solidify its seats gained in 2010, plus reconstruct the Detroit-area House seats.

The new boundaries paved the way for the dean of the Congressional Black Caucus to face the toughest primary of his career, as well as pit two junior House Members against each other.

Polls close at 8 p.m. EST in most of the Wolverine State, according to the Michigan secretary of state’s office. Some of the precincts in the state’s Upper Peninsula will close at 9 p.m. EST. Here are the races worth watching tonight:

Senate

Republicans view former Rep. Pete Hoekstra as the favorite to win the GOP nomination today over his top competitor, charter schools executive Clark Durant. The winner faces Sen. Debbie Stabenow (D) this November in a race Roll Call rates as Likely Democratic.

Hoekstra initially stumbled over his campaign’s racially insensitive Super Bowl spot. Even though voters are still familiar with the fallout of this ad, it wasn’t enough to doom his primary candidacy.

Hoekstra’s geographical advantage is more significant: He hails from western Michigan, an area rich with Republican voters. But all over the state, Hoekstra is better known among Republicans from his failed gubernatorial bid last cycle.

Durant has no comparable geographical base. Instead, he has commanded support from the lion’s share of national conservative players such as FreedomWorks and Sen. Mike Lee (R-Utah). But a couple of other minor candidates split the anti-Hoekstra vote, diminishing Durant’s chances.

Hoekstra led Durant 51 percent to 27 percent in a late July EPIC-MRA poll.

Hoekstra’s margin will probably not be that large. Durant saved significant resources for the final two weeks of the race, plus a super PAC supported him with almost $700,000 in additional independent expenditures.

Nonetheless, Republicans will be surprised tonight if Hoekstra is not their nominee.

House

3rd District

An under-the-radar Democratic primary for this central Michigan seat turned into a ruthless, expensive and ideological battle between former state Rep. Steve Pestka and Trevor Thomas, an aide to former Gov. Jennifer Granholm (D).

And it’s probably all for naught: Whoever wins the nomination will probably lose to freshman Rep. Justin Amash in this Republican-leaning district.

Democrats expect Pestka to prevail because he has run a better-funded campaign. The former judge loaned his campaign almost $600,000.

Thomas, who is openly gay, has presented himself as the true progressive in the race. He’s attacked Pestka as a conservative, specifically targeting his anti-abortion position (Pestka argues he is personally anti-abortion but would not legislate that way).

When Republicans redrew Amash’s district, they made it slightly more Democratic by moving Battle Creek into it. Michigan Republicans privately gripe about Amash’s allegiances to the movement of Rep. Ron Paul (R-Texas), but they still don’t view him as vulnerable under the new lines.  

National Democrats suggest Amash is vulnerable and have targeted him in press releases. But they have yet to reserve any airtime in the district — a signal the party is not yet ready to invest in the winner of this primary.

5th District

Many Democrats have been waiting for 18-term Rep. Dale Kildee (D) to retire so they could run for this eastern Michigan stronghold. The party expected several ambitious Democrats to line up for the chance to represent this safe seat.

It didn’t work out that way at all. Several Democratic candidates initially started campaigns. The field included formidable Democrats, including former Rep. Jim Barcia (Mich.), a five-term Member who more recently served in the state Legislature.

But former Genesee County Treasurer Dan Kildee slowly cleared the field by the filing deadline. The retiring Congressman’s nephew will walk into this House seat in November.

6th District

Early this cycle, conservatives zeroed in on Energy and Commerce Chairman Fred Upton as one of their top House targets. They viewed his potential loss as a conservative trophy prize if

his 2010 opponent, former state Rep. Jack Hoogendyk, could run a stronger campaign this cycle.

At first, it didn’t look good for Upton.

He defeated Hoogendyk by 14 points in the 2010 primary. Last November, the deep-pocketed Club for Growth publicly encouraged Hoogendyk run again. A few months later, the conservative group spent $50,000 blasting the Congressman in his district.

But this primary fizzled fast. Hoogendyk’s campaign never raised enough to respond when Upton started to attack. A few weeks before the primary, Hoogendyk reported less than $22,000 in the bank (about 1.3 percent of Upton’s cash on hand). The club never endorsed Hoogendyk or spent any more on his behalf.

Third-party interest groups, such as the American Optometric Association Political Action Committee, spent heavily for Upton — about $277,000 in independent expenditures.

Upton led Hoogendyk 61 percent to 31 percent in an EPIC-MRA poll of 800 likely primary voters taken July 28-29.

Republicans will be very surprised if Upton loses tonight.

11th District

This exurban district hosts the strangest House primaries in the country.

Republican officials support a write-in candidate, former state Sen. Nancy Cassis, over the only candidate on the GOP ballot, reindeer rancher Kerry Bentivolio.

Recent polling shows Cassis has a shot, but write-in campaigns are historically difficult and unpredictable. She must also counter more than $700,000 in independent expenditures on behalf of Bentivolio from national libertarian and tea party groups.

The mess started in June after Rep. Thaddeus McCotter submitted a faulty petition to get on the GOP primary ballot and dropped his re-election bid. He later resigned, prompting a Sept. 5 special primary to replace him.

In less than two months, this House race became a battleground for outside spending and an ideological fight among Michigan Republicans.

Meanwhile, Democrats have their own problems. The local party backs internist Syed Taj for the nomination. Taj is favored to win, but Bill Roberts, a Lyndon LaRouche supporter, is also running.

If Bentivolio wins, some Republicans believe Democrats have a shot to pick up the seat. But if Roberts pulls an upset, Republicans will almost certainly hold the seat regardless of their nominee.

13th District

Rep. John Conyers (D) faces one of the toughest primary challenges of his career today. Democrats expect him to win the nomination — but not by the overwhelming margins he has had in his past 24 races.

The Congressional Black Caucus dean has had his fair share of personal problems during the past couple of years. His wife, a former city councilwoman, went to prison for corruption. A local television station highlighted his unkept property in Detroit.

What’s more, the redrawn 13th district includes new suburbs on Detroit’s west side. These working-class, mostly white voters are not familiar with Conyers as the civil rights hero voters know downtown.

The geographical changes presented the perfect opening for his chief primary opponent, state Sen. Glenn Anderson. From his base in suburban Westland, Anderson attempted to run a spirited campaign against Conyers. He benefits from two urban candidates also running in the primary.

But it still doesn’t look like he can defeat Conyers — at least not this cycle. Recent polling suggests Conyers will win re-election in this heavily Democratic, black majority district. The Congressman got 57 percent, while Anderson scored 17 percent in a recent Detroit Free Press poll conducted by EPIC-MRA.

14th District

After Republicans dismantled Rep. Gary Peters’ district in their redraw, the suburban Democrat sought re-election in this downtown Detroit district. Peters viewed this as his best option for re-election because part of the 14th district included territory Peters represented in the state Senate.

It looks like he was right. Democrats expect him to defeat freshman Rep. Hansen Clarke in today’s primary. This November, the nominee will almost certainly win this heavily Democratic, majority-minority district.

Clarke lived in the neighboring 13th district when Republicans announced the new map. But he decided to run in the 14th district because more of his current territory is there. Several moths ago, Clarke  moved into the 14th district.

Clarke started off as the downtown Detroit candidate, but Peters ran a better campaign. Peters combed the redrawn 14th district, working diligently for the support of black churches. He picked up support from organized labor. He’s been running television advertisements in heavy rotation for many weeks.

Peters also crushed Clarke in fundraising. As of two weeks ago, Peters reported raising $1.9 million, plus had $530,000 in the bank for the final push. Clarke reported raising $699,000 and had just $56,000 in the bank at the same time.