Throughout Illinois' 172-year existence, the state has occasionally suffered a knave, a fool, a felon or a fraud as governor. But it's never had a veritable eunuch -- a totally impotent governor.

That may change in 2010. If the Democrats gain additional Illinois House seats, giving them a 71-47 majority or better, and retain their current 37-22 Illinois Senate edge, they would have the requisite three-fifths super majority needed to override a governor's veto and pass legislation in overtime sessions. The next governor, even if a Democrat, would be totally subservient to the General Assembly.

Such a situation would devastate the Republicans. The Democrats would draw new legislative district lines in 2011, after the 2010 census, and even if a Republican governor vetoed the map, they could override the veto. The Republicans could dwindle to fewer than 20 senators and barely more than 40 representatives. To survive and remain viable, the Republicans in 2010 must win the governorship and crest 50 House seats.

According to Springfield sources, at least 10 Republican-held House districts are in some jeopardy next year, as are nine Democratic seats.

The Republicans' zenith was 1994, when they picked up 13 seats for a 62-54 majority. They have frittered away 16 seats, losing five in 1996, two in 1998, four in 2002, one in 2006, one defector in 2007, and four in 2008, while gaining one in 2004. Two incumbents -- Beth Coulson (R-17) and Dave Winters (R-68) -- are expected to seek higher office in 2010.

But the Republicans are optimistic. Their legislative candidates underperformed by 10 percent in 2008, due to voter fatigue with Republicans and deflation of their base. The Democrats, however, overperformed by 10 percent, benefiting from extreme voter intensity and first-time voter enthusiasm for Barrack Obama, which boosted turnout to the 80 percent level. In 2010 turnout will drop to the normal 60 percent, and it will be the Republican base that will be intense and motivated. Here's the outlook:

Ten Republicans won with less than 55 percent of the vote in 2008, four of whom are from DuPage County. "It was a horrendous year for us," said one Republican operative. "Anybody who survived 2008 will certainly win in 2010."

17th District (Glenview, west Wilmette, north and east Skokie, parts of Morton Grove, Evanston, Winnetka, Northbrook, Golf and Glencoe): Coulson, first elected in 1996, has proven herself durable and unbeatable. But she barely wins, getting 51.5 percent of the vote in 2008, 59.3 percent in 2006, 53.9 percent in 2004 and 50.9 percent in 2002. She is now poised to run for Mark Kirk's (R-10) congressional seat.

If the seat opens, a flock of Democratic losers -- Michele Bromberg (2004), Judith-Rae Ross (2006) and Daniel Biss (2008) -- will try again. The Republicans have no obvious successor. The outlook: Likely Democratic pickup.

68th District (north Rockford suburbs, Loves Park and rural areas): Winters is running for lieutenant governor. He won with 59 percent of the vote in 2008, due to his personal popularity, but the district went for Obama, and the Democrats will be competitive. The likely Republican candidate is Rockford police detective John Cavello. The outlook: The Democrats will spend lots of money. Toss-up.

96th District (southwest DuPage County, Naperville): Freshman Republican Darlene Senger won by just 641 votes in 2008, getting 48.8 percent of the vote in a three-way race. Naperville is evolving into a cosmopolitan suburb resembling Oak Park and Evanston, with lots of eateries and plenty of independent and liberal voters. But Democrat Dianne McGuire, the 2008 loser, unwisely ran for Naperville Township clerk in 2009 and got crushed -- undermining her credibility for a 2010 comeback. The outlook: Senger is a solid favorite.

53rd District (western Cook County and southern Lake County, parts of Buffalo Grove, Arlington Heights and Prospect Heights): Republican incumbent Sid Mathias, who was first elected in 1998, faced a "perfect storm" in 2008 -- a Democratic wave, a credible and well funded female foe, and a listless Republican base. Mathias is a former Buffalo Grove mayor with a liberal record on social issues. The district went for Obama, who got more than 60 percent of the vote, but Mathias eked out a 3,545-vote victory, getting 52.5 percent of the vote. The outlook: Expect Mathias to rebound to his usual 60 percent in 2010, but if the Democrats draw the map, Mathias will be a goner in 2012.

45th and 46th Districts (Northeast DuPage County: Glendale Heights, Carol Stream, Addison, Elmhurst, Wood Dale): Demographic change, especially Hispanic voter growth, has put incumbents Franco Coladipietro (R-45) and Dennis Reboletti (R-46) in grave danger; the former won by 1,874 votes (with 52.4 percent of the total) in 2008, and the latter by 964 votes (with 51.2 percent of the vote). In 2006, however, those districts went Republican by, respectively, 57.2 percent and 50.6 percent. Reboletti's district, with a large minority population, eventually will flip Democratic. The outlook: 2010 looks like a Republican "wave" year, boosting every Republican's vote by 5 to 10 percent. Both should win.

65th District (Park Ridge, Des Plaines): Like Mathias, Republican Rosemary Mulligan faced excruciating pressure in 2008 yet managed to win by 3,594 votes, getting 54.6 percent of the vote. Mulligan's liberal record on social issues inoculated her against the Obama tide. First elected in 1992, Mulligan is running again in 2010, but she likely will retire in 2012. If the Democrats control the map, they will add part of Chicago's 41st Ward to her district. That would put Chicago Republican Mike McAuliffe (R-20) into a new area, where he would be vulnerable to a suburban Democrat. The outlook: Mulligan is safe.

69th District (Boone County and east Winnebago County; Belvidere): Incumbent Republican Ron Waite, who was first elected in 1994, won by 1,383 votes, with 51.8 percent of the vote in 2006, but he upped that to 5,218 votes (54.6 percent) in 2008 against the same opponent. The Democrats blew their chance. The outlook: Waite is secure.

61st District (northern Lake County, stretching from Zion to Fox Lake, including Lindenhurst, Antioch and Winthrop Harbor): This should be solid Republican turf, but Republican incumbent JoAnn Osmond won by 2,251 votes, with 52.3 percent of the vote in 2008, after being unopposed in 2006 and winning by 11,463 votes (63.1 percent of the total) in 2004. The outlook: Having survived 2008, Osmond is favored.

Among the Democrats, two incumbents have resigned, one has retired, two are expected to run for statewide office, and five are deemed vulnerable. In a best-case scenario, the Republicans could win nine seats. Here's the outlook:

56th District (Schaumburg, Roselle): The Republicans' bete noire, the much-reviled and detested party switcher Paul Froehlich, is retiring amid whiffs of scandal. After years of internecine warfare, the local Republican organization is in tatters. Froehlich quit as the Schaumburg Township Republican committeeman when he defected, but now he has poisoned the Democrats. The Republicans have united behind Ryan Higgins, a 28-year-old attorney from a prominent family. The outlook: Likely Republican pickup.

43rd District (Kane County: Carpentersville, Elgin): Demographic change aids the Democrats, particularly Hispanic growth in Elgin. Democrat Keith Farnham won by 295 votes in 2008, getting 49.1 percent of the vote and defeating 6-year incumbent Ruth Munson, but Munson already was in the crosshairs, having won by 1,137 votes (with 53.5 percent of the total) in 2006 and 387 votes (50.8 percent of the vote) in 2004. The outlook: Turnout was close to 80 percent in 2008. If it recedes to 60 percent in 2010, a Republican could win.

63rd District (western McHenry County: Harvard, Woodstock, Wonder Lake): Incumbent Democrat Jack Franks, a fiscal conservative and a virulent critic of Rod Blagojevich, is almost certain to run statewide in 2010. According to Democratic sources, Franks believes he could win a three-way primary for governor, running to the right of Pat Quinn and Dan Hynes and building a suburban/Downstate coalition. The outlook: If Franks bails, the Republicans win the seat.

71st District (western Illinois: East Moline, Fulton): Incumbent Democrat Mike Boland is no bundle of charisma, but he could win the Democratic nomination for lieutenant governor, particularly if two black Chicago Democrats -- state Representative Art Turner and Alderman Sandi Jackson -- split the black and liberal Chicago-area vote. The Republicans have recruited Rock Island County Board member Rich Morthland. The outlook: With Boland gone, a Republican pickup.

98th District (northern East Saint Louis suburbs): Incumbent Democrat Gary Hannig was appointed the state transportation director and replaced by his wife, Betsy Hannig. She pledged to serve to the end of his term, but she now is expected to run for reelection. Jack Marzotti, the chairman of the State Employees Retirement System, a major fund-raiser for Blagojevich, also wants the job. The Republican candidate will be Wayne Rosenthal, a brigadier general in the state Air National Guard and a local college trustee. The outlook: The Democrats are divided. Rosenthal will win.

112th District (Downstate: Edwardsville, Collinsville): Incumbent Democrat Jay Hoffman was Blagojevich's floor leader and chief apologist. That connection enabled him to raise $700,000 in 2008 and win by 8,142 votes, with 57.3 percent of the total. Republican Dwight Kay is back for a second crack. The outlook: Disliked and detested, Hoffman is 2010's Humpty Dumpty. He'll lose.

Also vulnerable are first-term Democrats Mark Walker, who won with 52.5 percent of the vote, Emily Klunk-McAsey (58.6 percent) and Jehan Gordon (52.9 percent) -- all riding the Obama wave.

My prediction: The Republicans win four seats, slicing the Democrats' majority to 66-52.