AUSTIN (KXAN) — Lt. Gov. Dan Patrick and his allies are picking sides in primary races that will likely decide who fills the 31-person Texas Senate.

The GOP is so dominant in Texas that the real fight for power is in the primary. It’s rare that sitting state leaders pick a side in their own party primaries but this year both Patrick and Gov. Greg Abbott are putting resources behind their brand of Republican.

The outcome of these races will determine how easy it is to pass policies capping local property tax growth and allowing families to use state dollars for private schools.

Patrick’s team working against incumbents

In the North Texas Senate District 30, Wichita Falls incumbent Craig Estes is challenged by Frisco Rep. Pat Fallon. Campaign finance reports indicate the lieutenant governor has picked a side. Patrick’s political arm, Texans for Dan Patrick, donated around $17,000 worth of polling for Fallon.

In an NBC 5 Dallas debate Estes spoke his mind unprompted. “The donation in-kind from Dan Patrick amounts to nothing more than a bribe to hire a ‘yes man’ in the Texas Senate, a puppet. The people of Senate District 30 are outraged over this” said Sen. Estes.

His opponent called that comment “disgusting.” Political spokesman and strategist for Patrick, Allen Blakemore, didn’t want to add a comment.

Craig Estes, left, Dan Patrick, center and Pat Fallon, right. (Official Photos)

Estes voted alongside the lieutenant governor nearly every time. However, one notable difference was when Estes abstained from a vote scrapping a rule requiring a two-thirds majority to pass Senate bills. Without that rule, conservative policies sailed easily through Patrick’s Senate.

Also in North Texas, Amarillo Republican Kel Seliger is up against Mike Canon from Midland. These two faced off last time and Seliger won in a nail-biter. This time, however, there’s a third candidate, Victor Leal, from Amarillo.

According to state ethics reports, Leal and Patrick have the same political consulting team, Blakemore & Associates, and their campaigns work out of the same building.

Patrick has been the driving force behind limiting the growth of city property taxes and allowing tax dollars to go to private schools. Seliger has voted against both of those issues.

Seliger says Patrick’s consultant, Allen Blakemore, runs a private business and can work for whoever he chooses. Blakemore didn’t want to add a comment.

But while Patrick’s allies and associates are working to oust him, Sen. Seliger doesn’t think Patrick himself is involved.

“Nobody has called me to say the lieutenant governor will sleep better if somebody replaces you in the Texas Senate, even though that might be the case,” said Sen. Seliger.

“Generally the statewide officials in Texas stay out of the races of the incumbent members of their own party. Even if they don’t like them,” said Ross Ramsey, executive editor of the Texas Tribune, a non-profit newsroom dedicated to Texas policy and politics.

Both the Estes and Seliger races are on his “hot” races to watch. He says these moves by Patrick and his political team are strange because as president of the Senate, he already leads the most conservative lawmaking body in recent Texas history.

“Trying to knock off a couple of senators who weren’t with him 100 percent of the time, that are only around 90 percent of the time, it’s really, unusual,” said Ramsey.

Patrick backs like-minded senators

A coalition of business and education groups have supported challengers to two big city Republicans that often vote alongside the lieutenant governor’s priorities. Patrick has come to their defense.

Patrick ally Sen. Bob Hall, R-Edgewood, is challenged by Rep. Cindy Burkett, R-Sunnyvale. In early February, Patrick endorsed Hall in a campaign video — an action that could lead to financial contributions and campaign appearances before the primary.

“I need Bob back to help me deliver on conservative principles,” Patrick said in the video.

He did the same for Senator Joan Huffman, R-Houston. Huffman is being challenged by Kristin Tassin, president of the Fort Bend ISD Board of Trustees, in part because of her stance when it comes to “vouchers” or state tax dollars for families to use on private or home schools.

“As chair of the State Affairs Committee, she’s responsible for moving some of our toughest and most important bills,” Patrick said in a video.

He’s also weighed in on races that aren’t as competitive.

Tuesday, Patrick announced more endorsements for senators Robert Nichols, R-Jacksonville, Charles Schwertner, R-Georgetown, Paul Bettencourt, R-Houston, Kelly Hancock, R-North Richland Hills and Konni Burton, R-Colleyville.