Ohio Rep. Dennis Kucinich ended his very public flirtation with a run for the House in Washington yesterday when he opted instead to stay in Ohio and challenge fellow Democrat Rep. Marcy Kaptur in a newly drawn congressional district.

Redistricting is a process that roils Congress every ten years when the constitutionally mandated census is released. There aren’t going to be any more than the 435 current seats in the House of Representatives. But the U.S. population continues to grow. Some states – Ohio, Louisiana and New York – lose seats going into 2012 and others – Texas, Florida, Arizona – gain them.

Read more about Kucinich’s decision.

Read more about redistricting.

Even in states where there is no change in the number of seats, population shifts mandate newly drawn districts that can wreak havoc on long political careers.

As with Kucinich and Kaptur, two long-serving Democrats will have a standoff against each other to see who gets the opportunity to run in the general election.

Kucinich argued that since a large portion of the liberal voters in his district – he said 57 percent – are going to be in the new district that includes parts of his Cleveland and Kaptur’s Toledo, he can win.

We asked Case Western Reserve University Political Scientist Justin Buchler, a redistricting expert, to decode the Kucinich news.

ABC: Is Kucinich’s read of the redistricting correct – 57 percent of his liberal voters will be consolidated in one new district?

Buchler: It is hard to tell.  Turnout in congressional primaries is very idiosyncratic, and since neither Kaptur nor Kucinich regularly face competitive primaries, we don’t really know what the Democratic primary electorate will look like in a potentially competitive primary in a newly redrawn district.  We can look at raw population, but that doesn’t really tell us how many Democratic primary voters will come from either incumbent’s district.  So, you shouldn’t really trust any estimate of this type.

ABC: How are Kucinich and Kaptur different?

Buchler: Kaptur is not exactly a moderate, but Kucinich is significantly more liberal.  He also has a higher public profile.  Both could help him in a primary, but again, it is hard to predict the primary electorate in a heavily redrawn district.

ABC: Has the GOP won redistricting in Ohio? Republicans control both the legislature and the governor’s mansion there and while two long-serving Democrats will square off, two freshman Republicans could also face each other in a primary.

Buchler: They will win a disproportionate majority of House districts.  That is something of a victory, but the plan itself is probably less biased than it could have been.

ABC: Is there a good way to describe how this state-by-state process is playing out nationally?

Buchler: Republicans control the process in most states.  They are taking some partisan advantage nationwide, but they have a natural advantage anyway because Democratic voters happen to be geographically packed in urban areas.  That makes it easier to spread Republican voters out more efficiently than Democratic voters, so it is hard to tell how much of the advantage is caused by explicit manipulation and how much of the Republican advantage is caused by simple political geography.