A supporter of U.S. Senate candidate Christine O'Donnell holds a… (Mark Wilson, Getty Images )
Reporting from Los Angeles — Voters in seven states and the District of Columbia cast ballots Tuesday in the final round of primaries that will shape the midterm elections and, perhaps more interestingly, could help define the political parties for the next several years.
For Democrats, Tuesday's vote is much like a bank shot on a pool table as they hope that the conservative tide of the "tea party" movement helps elect candidates who will have a hard time appealing to independents, thus aiding Democrats fighting to continue their control of Congress.
The stakes are equally high for the GOP, favored in the polls to wrest control of at least the House of Representatives. The party's establishment will also at some point have to figure out how to deal with the growing number of internal challengers if Republicans are to have a united front down the road.
So far, enthusiastic outsiders and deep conservatives have run successful challenges in Senate campaigns in at least four states, Colorado, Nevada, Kentucky and, especially surprisingly, in Alaska. So it is no accident that observers are keenly watching two key GOP races with similar templates in New Hampshire and Delaware.
In both states, party favorites face challenges from their right. New Hampshire lawyer Ovide Lamontagne has been embracing tea party principles in his effort to defeat front-runner Kelly Ayotte, a former state attorney general, for the Republican nod to run for the seat being vacated by Republican Sen. Judd Gregg. In Delaware, Republican Rep. Michael N. Castle, a former governor, is being challenged by Christine O'Donnell, another tea party movement favorite.
Castle and Ayotte are considered to have better shots against Democrats in November, upping the possibility of the GOP perhaps winning control of the Senate. So, many national Democrats are rooting for the outsiders to win Tuesday.
But two more conservative victories carry a deeper risk in continuing to push the GOP to the right. At some point, Republicans, still the minority party in enrollment, need independent help to overcome the Democrat voter edge.
Also at stake is perhaps the personal fortunes of possible presidential candidates in 2012. Former Alaska Gov. Sarah Palin has endorsed five candidates in primary races, including Ayotte and O'Donnell. She has endorsed long shots in Maryland and in a New York congressional district. She is also backing a favorite, former reality TV star Sean Duffy, for the nomination for an open congressional in Wisconsin.
While she has backed losers before, Palin has polished her superstar status in this election cycle, especially for her role in helping Joe Miller win the GOP nomination, unseating Sen. Lisa Murkowski in Alaska.
Among other key races is the primary battle in Manhattan where Rep. Charles B. Rangel, already facing a House ethics hearing, is hoping to win re-nomination.
Other states having primaries will be Massachusetts and Rhode Island.