Last November, former Fresno Mayor Jim Patterson said running against incumbent Democrat Jim Costa in the newly created 16th Congressional District was "a fool's errand."

Today, Patterson said he's reconsidered that pronouncement -- and the accompanying decision not to challenge Costa.

"After doing quite a bit of homework and looking at the makeup of the district, I actually think there is an opportunity to beat Mr. Costa," Patterson said.

The about face comes after several prominent Republicans -- including Patterson -- considered and then rejected a Costa challenge. As of now, the only Republicans stepping up to challenge the longtime Fresno lawmaker are local attorney Brian Whelan and dairyman and business owner Johnny Tacherra of Burrel.

Patterson said the political landscape has changed just since last year, and he now says Costa is vulnerable on important issues such as the nation's budget deficits, his years in the state Legislature that set the stage for California's current financial struggles and "the absolute recklessness of high speed rail."

In fact, Patterson thinks that issue alone is enough to mount a campaign against Costa, who is in his fourth term in Congress.

Patterson acknowledged that the district -- which includes half the city of Fresno, as well as parts of Fresno and Madera counties and all of Merced County -- is drawn to favor a Democrat.

He said as much last November when he dismissed a possible Costa challenge. At that time, he also said Republican Reps. Devin Nunes of Visalia, Jeff Denham of Atwater and Kevin McCarthy of Bakersfield, as well as the National Republican Congressional Committee, were "not willing to target this seat."

At the time, he also said they needed to commit $2 million to make it competitive for a Republican.

Now, Patterson is backing off that statement.

"I think that comment was premature," he said. "I think I was hoping for deeper and broader support than what was initially offered. I think I misread it as a lack of support instead of seeing as a challenge to me to get serious -- and I am willing to get serious."