Two congressional races in the Houston area this fall could demonstrate how important, and overlooked, casting can be in a close election.

With a tough election ahead, Republicans were hoping a pickup of Tom DeLay's former seat in the 22nd district would put the party up one seat in Texas. That election isn't looking as straightforward as originally expected, and the GOP now has to worry about losing in the state's 7th district, a usually safe conservative seat represented by both George H.W. Bush and Bill Archer, and going down a seat in the state. How could this happen?

Even the most astute political prognosticators of the pundit class are sometimes unable to predict the events and attitudes that often set the stage for major upsets. And while clever strategies, such as the 1994 "Contract with America" that brought Republicans into power in the House after 40 years, and unforeseeable events, such as the numerous congressional scandals that shoved them back out of power in 2006, are behind the shifts in power, the importance of having the right candidates at the right time is what helps turn a tide into a tsunami.

In 1994, Democratic seats were captured by well-financed campaigns with smart, tough challengers such as Joe Scarborough, Saxby ChamblissClarence (Saxby) Saxby ChamblissLobbying World Former GOP senator: Let Dems engage on healthcare bill OPINION: Left-wing politics will be the demise of the Democratic Party MORE and J.C. Watts. In 1996, a group of credentialed Democrats like Navy Vice Adm. Joe Sestak, Chris Carney and others ousted Republicans. Though many factors led to the seat-switches, the strength of the challengers was key.

On a congressional level, the prospects are bleak for Republicans. The economy is the driving issue and many believe that the Republicans can't win on the economy. Saddled with President Bush's legacy and lacking a candidate at the top of the ticket who will bring votes home in many districts, the Republicans have needed encouragement. Texas-22, now held by Democrat Nick Lampson after a strange set of circumstances left the Republicans without a name on the ballot in the previous election, seemed one of the easiest races to switch.

With the election coming closer, there are signs that it may not be as easy as previously thought. In a hotly contested primary, Republican establishment support went to Pete Olson, who went on to win the primary. Olson does have a lot going for him, especially in terms of his experience serving with the military in Iraq. But his selection was over a local candidate with significant local support, and this occurred largely because of the support of Sen. John CornynJohn CornynRepublicans divided over legislation protecting Mueller Democrats mull audacious play to block Pompeo Overnight Energy: Senate confirms Bridenstine as NASA chief | Watchdog probes Pruitt’s use of security detail | Emails shine light on EPA science policy changes MORE and former Sen. Phil Gramm.

The seat may still go Republican, but signs are less promising than they should be at this point and the National Republican Congressional Committee (NRCC) has pulled back on its support for the race. The reasons?

First, in a "change" election a large advantage that Republicans had in challenging Lampson was his relatively long tenure in Congress. The challenger they selected is a former staffer of Sens. Cornyn and Gramm. Second, Lampson moved to be eligible to serve in district 22, something that is an obvious mark against the candidate. The candidate they selected has, according to a report covered in The Hill, been voting in states other than Texas until recently, which makes it hard to take advantage of this weakness. Third, he has no case to make on the economy or hurricane relief, issues on the minds of voters (one of the local candidates they overlooked was an accountant and business adviser).

Even if the Republicans do pick up Lampson's seat, a seat that demographically should be their seat anyway, they're in trouble a few miles away in the 7th district. This seat is arguably where the Republican revolution in Texas first took hold, electing George H.W. Bush as one of the state's first congressional Republicans since Reconstruction. With a Cook Partisan Voting Index of +15 for the Republicans, no congressman not caught choking his mistress should have much trouble.

Why is it a close race?

Good casting. The incumbent, Rep. John Culberson, is a conservative Republican who appears to match the conservative district fairly well. Yet in a recent public poll that occurred before the full brunt of the economic crisis hit, Culberson polled only 7 percent ahead of his challenger with support in the low 40s. He has also been beaten in fundraising every quarter.

The previous Democratic challenger was a high school debate teacher without any national support, significant resources or name ID. This year the challenger is Michael Skelly, the type of candidate whom incumbents fear. Having created a successful wind-energy business, Skelly started off with three advantages: the ability to self-finance early campaign operations, a strong case that he understands the economy and energy (Harvard MBA and energy business owner) and support from the Houston energy and business establishment.

Add to those obvious advantages that he immigrated to this country when he was 2 years old from Ireland (giving him an interesting personal narrative when he speaks about "the American Dream") and it starts to explain why the race is suddenly competitive. Of course, the Democratic Congressional Campaign Committee (DCCC) can't take credit for finding Michael Skelly, though they have shifted support in his direction.

The economic crisis already puts Culberson, like many Republican incumbents, in a tough position. Having a challenger who's a Harvard MBA grad with a wind-energy business positioned to take advantage of these conditions could mean a shock in Texas.

At the end of the day, national parties can't decide whom voters are going to select in party primaries. Nevertheless, parties can work to draft smart challengers in promising districts. In an election year that could see a further realignment in Congress, one great and one not-so-great challenger in suburban Houston could mean the difference between a net gain of one seat for Republicans and a tie or even a net loss.

If you don't think casting is important, explain to me why movies with Will Smith or Mark Wahlberg always do so well? Hollywood knows how to cast a winner.