Districts from which the conservative "Tea Party" Congressmen arise are unlikely to vote out their man, because they are doing exactly what they were elected to do. They are safe, safe, safe. Unless their constituents have some kind of epiphany. Part of the Republican credo is to reduce government, and maybe take it down several pegs, not just a few.
In more moderate districts, a Republican incumbent or candidate always lives in mortal dread of the primary, where he/she faces a high conservative hurdle.
So politics in the US are highly polarized, and likely to stay that way failing much creative redistricting. The notoriety of folks such as Cruz make it more likely for Republicans to regain the White House, but also to lose the House of Representatives, I've heard some analysts say.
In the event of a default, nobody is exactly sure of the consequences - except for one thing: interest rates will rise. This will be a silver lining for savers, who have seen interest on their nest eggs tumble to well under 1%, an extraordinarily low historical rate. With default, Americans will learn the true meaning of austerity, and they may not like it. Foreigners holding US sovereign debt need not worry quite so much, since they will be paid first.
As for "Obamacare", it was a law passed without a particle of Republican input as to its contents. It appears to have many rough edges and problems as it goes into effect. It will take about a year before it is possible to tell whether it is a success or catastrophic failure due to young people failing to sign up or re-up after they see the costs.
In short, it is a giant roll of the dice on all sides. There will be blood, and much gnashing of teeth.
What with no real recovery to the 2008 crisis, growing poverty and disappearing middle class, plummeting confidence in government only added to by the NSA scandals, and a growing atmosphere of corruption, it is obvious the current state of the union is undesirable and unsustainable. What, if anything, will truly fix it, no one can say.
However, there is a ray of hope from Colorado, where the first crop of industrial hemp in the US since 1957 is being harvested. IMHO what we need are many new industries based on this highly useful weed in the sectors of food, fuel, medicine, clothing, paper and building materials. And 5% interest on savings.