The court wrote that "that the uncontroverted contents of Taylor's September 3 letter timely satisfy the statutory requirements for withdrawal."
The court's ruling is a setback for vulnerable Sen. Pat Roberts (R) because it enables his main opponent to pursue anti-Roberts voters without serious competition.
Long seen as a safe Republican hold, Kansas has suddenly become competitive in recent weeks, amid struggles by Roberts. Republicans need to gain six sets to win the majority. A GOP loss in Kansas could be a devastating setback.
In a statement, Roberts campaign manager Corry Bliss blasted the court's ruling and charged it was politically motivated.
"This is not only a travesty to Kansas voters, but it’s a travesty to the judicial system and our electoral process," said Bliss.
Roberts's main challenger is independent candidate Greg Orman. Had Taylor's name stayed on the ballot, the Democrat could have drawn anti-Roberts votes that would probably otherwise go to Orman.
Some Democrats unaware that Taylor ended his campaign might have voted for him if his name was on the ballot simply because of his party affiliation.
A Fox News poll released Wednesday showed Taylor pulling 11 percent of the vote, with Roberts and Orman running neck and neck. A former Democrat and Republican, Orman will not say which party he'd caucus with if elected to the Senate.
In a statement, Orman campaign manager Jim Jonas said the ruling does not change his outlook.
"No matter who's on or off the ballot, Greg Orman is running as an Independent against the broken system in Washington that has failed Kansas and failed America," said Jonas. "Kansas voters from across the political spectrum are fed up with the mess in Washington, and that's why Republicans, Democrats and Independents are supporting Independent Greg Orman for Senate."
Taylor abruptly ended his bid on the last day for ballot changes, freeing Orman to effectively have a clear shot at Roberts.
Roberts, who recently shook up his campaign staff, is struggling against the perception that he has lost touch with Kansas. His primary opponent repeatedly slammed him for not staying in his own home when he is in the state.
Here's the court's ruling: