Prosecutor Ken Buck eked out a win in Colorado's Republican Senate primary Tuesday over former Lt. Gov. Jane Norton.

The AP declared Buck the winner. Buck won with 52 percent of the vote to Norton's 48 percent. 

Buck will face Sen. Michael BennetMichael Farrand BennetBipartisan lawmakers can rebuild trust by passing infusion therapy bill GAO to investigate Trump's voter fraud commission 2 election integrity commission members protest lack of transparency MORE (D) in November. 

The primary was too close to call heading into Election Day and it's one that will be remembered for some of the nastiest and most personal attacks of the primary season thus far.

Norton started off as the frontrunner, courtesy of her support from Republicans in Washington and backing from the National Republican Senatorial Committee (NRSC).

But in a cycle that has repeatedly punished candidates with insider status, that support became a negative as Buck started hammering Norton as the establishment pick.

His support, meanwhile, came largely from conservative and Tea Party activists as the establishment line caught on with GOP primary voters. But far from hiding behind her cash advantage, Norton went right after Buck's strength and hit him with several negative TV ads.

After Buck was caught on tape calling those who questioned whether President Obama was born in the United States "dumbasses," Norton hit him for "insulting" members of the Tea Party.

And after Norton suggested Buck wasn't "man enough" to run his own attack ads against her, instead standing behind third-party groups, Buck told supporters at a campaign event they should vote for him because he "doesn't wear high heels." That comment elicited another Norton negative spot.

Both candidates had endorsements from major figures in the Republican Party. Sen. John McCainJohn Sidney McCainGOP rushes to cut ties to Moore GOP strategist: 'There needs to be a repudiation' of Roy Moore by Republicans World leaders reach agreement on trade deal without United States: report MORE (R-Ariz.) campaigned with Norton the weekend before the race and conservative favorite Sen. Jim DeMint (R-S.C.) campaigned with Buck.

Despite a negative primary on the Democratic side, the Democrats are convinced the GOP contest has done plenty of damage to the nominee. Democrats, in-state and nationally, have catalogued the litany of statements from Buck over the course of the primary it thinks will alienate independent voters.  

In a Democratic Senatorial Campaign Committee memo e-mailed after Tuesday's results, Sen. Robert MenendezRobert (Bob) MenendezIn judge's 2010 Senate trial, Menendez was guilty of hypocrisy Excused Menendez juror: 'I don't think he did anything wrong' We don't need a terrorist attack to know diversity program has to go MORE (D-N.J.) said Buck "joins the ranks of Rand PaulRandal (Rand) Howard PaulGOP senator asks to be taken off Moore fundraising appeals Red state lawmakers find blue state piggy bank Prosecutors tell Paul to expect federal charges against attacker: report MORE, Sharron Angle, and Ron JohnsonRonald (Ron) Harold JohnsonDemocratic Homeland Security members request additional DHS nominee testimony Key differences between the Senate and House tax plans Senate panel delays vote on Trump’s Homeland Security pick MORE as out-of-touch extremist candidates more concerned with imposing a strict social doctrine than with getting our economy moving again."  

NRSC Chairman John CornynJohn CornynAfter Texas shooting, lawmakers question whether military has systemic reporting problem Overnight Defense: Lawmakers question military's lapse after Texas shooting | Trump asks North Korea to 'make a deal' | Senate panel approves Army pick Overnight Regulation: House passes bill to overturn joint-employer rule | Trump officials to allow work requirements for Medicaid | Lawmakers 'alarmed' by EPA's science board changes MORE (R-Texas) countered by assailing Bennet's voting record during his time in the Senate, saying he "eagerly toed the party line and embraced the policies that helped drive our national debt past a record $13 trillion during his brief appointment to the U.S. Senate."

The general election race is considered a toss-up.

—Updated at 11:51 p.m.