(AP) NEW YORK - The departure of four Democratic senators this year has cast a new _ and at times, unflattering _ light on governors and their power to fill Senate vacancies.

While governors must call a special election to replace members of the House who resign or die before their term is up, 38 states allow governors the sole power to appoint an interim senator, according to the National Council of State Legislatures.

Just nine states require a special election to fill a Senate vacancy. In three other states _ Hawaii, Utah and Wyoming _ governors must select a candidate from a list of prospective appointees submitted by representatives of the departing incumbent’s political party.

Choosing a new senator has led to considerable drama for the four governors tasked with doing so this year. All have weathered some level of opprobrium for their choices or for how they handled the selection, with one _ Rod Blagojevich of Illinois _ facing criminal charges for trying to barter President Barack Obama’s former seat for cash and favors.

"Politically, the choices made by the governors so far have been pretty odd," said Seth Masket, an assistant professor of political science at the University of Denver.

Most recently, New York Gov. David Paterson engaged in a messy, drawn-out effort to name a replacement for Hillary Rodham Clinton, Obama’s secretary of state. The process was largely dominated by a high-profile lobbying campaign by Caroline Kennedy, the 51-year-old daughter of President John F. Kennedy hoping to win the nod.

Paterson spent weeks vacillating publicly about Kennedy, at turns praising her intelligence while criticizing her lack of experience. The governor hinted openly that he would choose Kennedy, then contradicted himself later by saying he was still considering other candidates.

For her part, Kennedy appeared tentative and unprepared, and she abruptly withdrew her name from consideration for the seat Thursday. Her departure launched a war of recriminations between her allies and Paterson’s _ a spectacle that suggested Paterson had somehow lost control over the selection process.

Paterson announced Friday he had selected Rep. Kirsten Gillibrand, a moderate from the upstate region. But even that choice produced its share of grumbling.

Rep. Carolyn McCarthy, citing Gillibrand’s opposition to gun control, vowed to challenge her in the 2010 Democratic primary, or to find another candidate to do so. McCarthy came to Congress after her husband was killed and son wounded during a shooting rampage on the Long Island Railroad in 1993.

Gillibrand is also largely unknown in voter-rich New York City and its suburbs, where most of the state’s Democrats live.

"Gillibrand seems fine for her district, but this is a state where liberals can actually win statewide," Masket said. "It’s not clear why the governor wouldn’t pick someone more liberal."

In Illinois, Blagojevich prevailed in a high-stakes game of chicken with Democratic leaders by naming former Illinois Attorney General Roland Burris to Obama’s seat.

Senate Democrats had insisted that any candidate Blagojevich named would not be considered a legitimate replacement. They eventually relented and allowed Burris to be seated, but he remains tainted by his connection to Blagojevich and may not be the strongest candidate to withstand a Republican challenge in 2010.

While less visible than the Illinois and New York Senate replacements, retiring Delaware Gov. Ruth Ann Minner has withstood criticism for her choice to fill Vice President Joe Biden’s Senate seat. And Colorado Gov. Bill Ritter’s choice of a replacement for Ken Salazar, now Obama’s interior secretary, has also mystified some.

In Delaware, Minner selected longtime Biden aide Ted Kaufman to serve until a special election in 2010. Kaufman has made clear he will not run in the special election, clearing the way for Biden’s son Beau, the state attorney general currently serving in Iraq as a member of the Delaware National Guard.

In appointing Kaufman, a relative unknown to most Delaware voters, Minner passed over the state’s popular Lt. Gov. John Carney _ reinforcing the notion that the seat belongs to the Biden family and its loyalists.

In Colorado, Ritter chose Denver Public Schools Superintendent Michael Bennet to succeed Salazar, even though Bennet has never run for statewide office and is virtually unknown beyond Denver. The choice sets the stage for a strong Republican push for the seat in 2010.

Despite the inevitable missteps, allowing governors to fill Senate vacancies is generally a smart solution, said Jeff Bosworth, an assistant professor of history at Mansfield University in Pennsylvania.

"It’s atypical to choose a senator this way, but it’s worse to leave a state unrepresented for the time it takes to put together a special election," Bosworth said. "I can’t see a better system than leaving it to the governor. They’re elected, and if you don’t like what they did, don’t vote for them next time."