Republican Scott McInnis confirmed rumors today that he would drop out of the race for the U.S. Senate. As The Denver Post reports:

Scott McInnis dropped out of the U.S. Senate race today, leaving Republicans scrambling for a worthy challenger to Mark Udall in what was once considered the lone competitive race in the country.

“My decision is based on doing what is right for Colorado, and ultimately what is right for my family,” McInnis said.

McInnis, a former six-term congressman for the 3rd Congressional District, said he will remain “actively involved” in politics.

McInnis was the only announced Republican candidate for the U.S. Senate seat being vacated by the retiring Wayne Allard (Rep. Mark Udall is the only known candidate for the Democrats), but his candidacy didn’t even last a full three months. Insiders have long suspected that former Rep. Bob Schaffer had made up his mind to also enter the Senate race at some point, and McInnis may have been unsatisfied with the idea of running a tough primary campaign even before facing Udall in a race that is expected to be one of the most hotly contested in the entire country.

Schaffer may make his intentions public to run for Senate at some point soon, and Attorney General John Suthers may also jump in the race soon. Don’t listen to speculation that radio host Dan Caplis might run – he would be absolutely crushed in a GOP primary and isn’t generally taken seriously by state Republicans.

The likely scenario is that Schaffer runs unopposed for the Republican nomination, which sets up a much different race than McInnis-Udall might have been. McInnis is a moderate Republican – in the middle on issues like gay marriage, for example – while Schaffer is a tried-and-true social conservative. In a state where moderate Democrats have captured the last two top-ticket spots, the race before the race may be a run to the middle.