OKLAHOMA CITY (AP) — With the final candidates in place for November’s congressional matchups, Republicans focused Wednesday on a clean sweep of Oklahoma’s delegation, while Democrats looked to defend their only congressional seat and expressed cautious optimism that a second seat in Tulsa could be in play this year.

Democrats desperately want to hold on to the state’s 2nd Congressional District in eastern Oklahoma, where their nominee Rob Wallace, a 49-year-old veteran prosecutor, will face Westville plumber Markwayne Mullin, 35. The seat was left open when current U.S. Rep. Dan Boren, the lone Democrat in the state’s congressional delegation, decided not to seek a fifth term in office.

And while both sides acknowledge the open 2nd District is this November’s top political prize, Democrats are encouraged about their chances in the 1st Congressional District in Tulsa where a tea party-backed Republican, Jim Bridenstine, knocked off five-term incumbent U.S. Rep. John Sullivan in the GOP primary in June. That upset gave Democrat John Olson, a 35-year-old attorney and Afghanistan war veteran, an opening he believes he can exploit.

“I was fully anticipating running against John Sullivan, and this absolutely changes the dynamic to some degree,” Olson said. “It definitely makes things a lot easier than they would have been otherwise.”

The unexpected wrinkle in the 1st District race puts added pressure on Democrats to carefully divide their finite campaign resources.

Oklahoma Democratic Party Chairman Wallace Collins agreed the 2nd District is the top priority for the party this fall, but he added: “We’re certainly not ignoring the 1st District by any means.”

The Democratic Congressional Campaign Committee also has placed a priority on the 2nd District and sent out an email blasting GOP nominee Mullin just hours after the polls closed on Tuesday.

Even as Republicans were in Florida celebrating the nomination of Mitt Romney at the GOP’s national convention, Oklahoma Republican Party Chairman Matt Pinnell said activists were busy at work in the 2nd District with hopes of an all-red state delegation.

“We’re going to make sure our base understands that we can’t take this race for granted,” Pinnell said. “I’ve got volunteers on the doorstep as we speak. I have people on the phones as we speak. We know that we’ve got to work hard every day to make sure Republicans turn out, but also to make the argument for Markwayne Mullin to conservative Democrats and independents.”

Pinnell acknowledged Bridenstine’s upset of Sullivan in the 1st District makes that a race for an open seat, but he said he’s confident Bridenstine can keep the seat in the Republican column.

“Now, we can’t just sit in our La-Z-Boys and expect to win,” Pinnell said. “I tell my Republicans all the time — Democrats aren’t going to lay over and just let us have this race. We have to continue to work at this.”

As for Oklahoma’s other three congressional seats, even the chairman of the Oklahoma Democratic Party acknowledges incumbent Republican U.S. Reps. Frank Lucas in the 3rd District, Tom Cole in the 4th District and James Lankford in the 5th District will be tough to unseat in November.

“Obviously, a Democratic win in any of those other districts would be an upset of major proportions,” said Chairman Wallace Collins, who noted Democratic challengers in all three districts will have a major disadvantage in funding. “It’s going to be tough sledding over there.”