WASHINGTON (AP) — Republicans are poised to take control of the Senate, provided they avoid Election Day upsets and win at least three of a half-dozen close races they feel they are ahead.

The campaign map gives Republicans several ways of winning the six net seats they need to wrest the Senate majority from Democrats. How they can get there:

DON’T BLOW THE EASY ONES

It would be stunning if Republicans fail to grab three seats in states where veteran Democrats are retiring, and where President Barack Obama lost badly: West Virginia, South Dakota and Montana. Those three states should put the GOP halfway to its goal of six pickups.

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TARGET FOUR OTHER STATES OBAMA LOST

Republicans are running hard against Democratic senators in four other states Obama lost, three of them badly. Democrats Mark Pryor in Arkansas and Mary Landrieu in Louisiana look to buck the South’s continued drift toward the GOP. In Alaska, Mark Begich seeks re-election in a state the president lost by 14 percentage points.

Democrats feel slightly better about first-term Sen. Kay Hagan of North Carolina, a state Obama won in 2008 and lost in 2012.

GOP victories in three of these four states, added to the easy three, give them the magic six.

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DON’T GO BACKWARD

But if Republicans lose any seats they now hold, they will need to take more than six away from Democrats to gain the majority.

Republicans fret the most about Georgia, where Democrat Michelle Nunn and Republican David Perdue are battling hard to succeed retiring GOP Sen. Saxby Chambliss. In Kansas, independent Greg Orman might beat GOP Sen. Pat Roberts, but it’s possible Orman would align with the Republicans.

In Kentucky, Republicans see almost no chance that five-term Sen. Mitch McConnell will lose, despite massive spending on a race that’s drawn a lot of attention.

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WIN IN A FEW STATES MITT ROMNEY LOST

Republicans have a chance to grab Democratic-held seats in two or three states that Obama won in 2012. Their best shots are against first-term Sen. Mark Udall of Colorado, and in Iowa, where Democratic Rep. Bruce Braley is running to replace the retiring Sen. Tom Harkin. Democrats feel slightly better about fending off Republican challenger Scott Brown in New Hampshire, where Sen. Jeanne Shaheen seeks a second term.

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ENDURE UNCERTAINTY AND WIN RUNOFFS

Despite a lineup that favors the GOP, election night could be long, messy and uncertain. In Alaska, quirky vote-counting traditions could delay the final tally for a week. In Louisiana, a Dec. 6 runoff is likely between Landrieu and GOP Rep. Bill Cassidy, thanks to numerous third-party candidates and the state’s unusual election laws. In Georgia, a runoff would not be held until January.

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KANSAS DECIDES IT ALL?

In Kansas, Orman conceivably could dictate which party controls the Senate, provided he wins in Kansas and the other elections give Democrats 49 seats and Republicans 50. Should he decide to caucus with Democrats, they would control a 50-50 Senate, thanks to Vice President Joe Biden’s tie-breaking authority. Or Orman could give Republicans the all-important 51st senator.