(CNN) - In Delaware, the Republicans got the man they were looking for.
Rep. Mike Castle announced Tuesday that he'll seek the Senate seat once held by Vice President Joe Biden. What makes this race even more intriguing is that the nine-term congressman, who represents the entire state of Delaware, could face off next year against one of Biden's sons.
"It has never been more important for Delaware to have the strongest and most experienced leadership to represent us in Washington. We are best served by an experienced, independent voice and that is why I am announcing my intention to run for the United States Senate," said Castle at a news conference in Wilmington, the state's largest city.
Castle, a former two-term governor, said that his official campaign kickoff will come later.
Biden stepped down from the Senate late last year after his election as vice president. Ted Kaufman was appointed to replace Biden, but has said he won't run for election next year, leaving the seat open.
Democrats are now waiting to see if the vice president's son, Beau, declares his candidacy for the seat. The younger Biden is the Delaware attorney general. Last month he returned home after spending a year with his Army National Guard unit in Iraq.
"This is the only guy the Republicans were looking for in Delaware. This is a case where there was one person and only one person who could make this race competitive. It was all or nothing with Mike Castle," says Stuart Rothenberg, editor and publisher of the non-partisan Rothenberg Political Report.
With Castle's entry into the contest, Rothenberg is now characterizing the race as a "lean takeover" in its 2010 race ratings.
Polls of Delaware voters conducted earlier this year suggested that Castle led Beau Biden in a hypothetical general election matchup.
If the younger Biden does jump into the race, expect a high profile contest with national attention.
"The White House is very much involved in the 2010 elections whether it be in helping raise money or trying to clear the primary field in some states," said CNN Political Editor Mark Preston. "Vice President Biden doesn't want to see the seat he held since 1973 fall into Republican hands and he will do all he can to make sure that his son doesn't lose if he decides to run."