Republicans will likely retain control of the Kansas Senate after the 2012 election, but an ideological battle playing out in the August primary will decide which faction of the party will run the chamber. With the Senate in hand, conservative Republicans would have firm control of the state's agenda.

Primaries are shaping up in several of the state Senate districts that pit conservative Republican challengers against moderate longtime Republican incumbents. Conservative Republicans have been on the rise in Kansas since the 2010 election ushered in Gov. Sam Brownback (R) and a conservative-led GOP caucus in the state House of Representatives.

"What you have in Kansas is for 40 years moderate conservatives ran this state," said Burdett Loomis, a political science professor at the University of Kansas. "You had a coalition who ran the state that wasn't highly ideological. Brownback's election as governor is the most conservative of the modern era."

While the GOP already controls the Senate by an overwhelming 32-8 majority, Loomis noted that moderate Republicans have teamed with the Democratic caucus to block more conservative legislation, supported by Brownback and the House, by a series of one- and two-vote majorities. A move of four seats would give the conservative block the majority.

Many of the primary challenges are directed at the Senate's top Republican leaders, including Senate President Stephen Morris, Senate Vice President John Vratil, Assistant Majority Leader Vicki Schmidt and key committee chairs, including Tim Owens, who runs the judiciary panel.

"They dislike them very, very much," Loomis said of the conservatives' opinion of the moderates. "They take this notion of RINO [Republican in name only] seriously. They feel the moderates have voted with the Democrats and denied real Republicans the chance to govern."

Senate Republicans, for example, blocked Brownback's proposal to cut the state arts commission, putting money back in the budget , until the governor used a line-item veto to eliminate the funding. The Senate has also blocked Brownback's proposal to change the state's selection process for appeals court judges, from the governor choosing off a selection committee's list to the governor making his own picks, who would then face Senate confirmation.

Among the other issues likely to be debated in the primary campaign are the state's school funding formula, which Brownback is seeking to alter on the ground that Kansas cannot afford the current formula, and reduction of the state's income tax rates . Brownback is scheduled to unveil his tax plan at the start of next year's legislative session, and Senate Republicans announced this week that they are forming a committee to seek citizen input on any tax changes.

While much of the debate centers on Brownback's agenda, that doesn't mean the first-term governor is guiding the primary challenges. State Rep. Greg Smith (R) said Brownback didn't ask him to take on Owens in the primary. And Loomis said he has not seen the governor being involved, adding that the challenges are largely movement-driven.

"He doesn't have to," Loomis said of Brownback. "There is enough energy and money in the GOP."

Loomis predicted that outside conservative groups will likely get involved in the primaries, which he said is unprecedented in Kansas legislative fights. He also said he expects the moderate Republicans working with Democrats to raise the funds to compete.

Although the moderate Republicans aren't likely to shrink from the fight, the conservatives plan to launch upwards of seven challenges.

"All that stands between them and total control is the Senate," Vratil said.