Charlie Geren is NOT conservative.

You do not have to take my word for it.

Young Conservatives of Texas rank him among the least conservative out of 84 Republicans in the Texas House (excluding the speaker).
Charlie Geren was the lowest-rated Republican in Texas Family Project's legislative rantings for this last session with 52 percent out of 100 (a grade of "F"), a mere 4 percentage points higher than Democrat State Rep. Eddie Morales.
Texas Values Action’s Faith & Family Scorecard gave him the lowest score of all Republicans in the house.
Texans for Fiscal Responsibility gave Charlie Geren a grade of “F.”
Texas Right to Life gave him the 3rd worse score of any Republican in the house.
In 2018, Texas Right to Life also ranked Charlie Geren a "pro-life fraud" and a "disappointment," arguing he had "failed the pro-life movement, prioritizing power over principle."
He was ranked as the 4th least conservative Republican in the Texas House by the Rice University professor Mark Jones and published in the Texas Tribune.

This image is based on all record votes taken during the 88th Legislative Session, comparing between House Representatives. If a Republican disagrees more often with Republicans than with Democrats, that Republican is named in the map and their district is displayed in a shade of purple. The darker the purple, the more disagreement they have with other Republicans rather than Democrats. Click on the image for more details.

Of the top 10 House members Charlie Geren voted contrary to, 9 of them are Republicans.
Of the top 20 House members he voted contrary to, 16 of them are Republicans.

Source: Texas Legislature Online via grassrootspriorities.com

Prior to the 88th legislative session, the Republican Party of Texas (RPT) voted to ban Democrat chairs to ensure that all legislative Republican priorities are given a fair opportunity to become law. Early during the last legislative session, a lawmaker proposed changing the rules of the House to disallow minority party members from holding committee chairmanship positions. Per the Texas Scorecard:

"On the first day of the legislative session in January, two Republican state representatives called on their fellow conservative lawmakers to listen to their constituents and pass a rule aligned with the RPT’s priorities.

"On the second day of the legislative session, a lawmaker proposed changing the rules of the House to disallow minority party members from holding committee chairmanship positions.

"However, a point of order made by State Rep. Charlie Geren (R–Fort Worth) was sustained by House Speaker Dade Phelan (R–Beaumont), which killed the proposal before a vote could be taken."

Dade Phalen later appointed eight Democrats to chairmanships.

Here is another example of Charlie Geren proving he is NOT conservative. CSHB 3782 was a bill that created a Border Security Advisory Council. In committee, it was amended by Rep. Ryan Guillen (D-HD31) to make the Advisory Council an equal split of Democrats and Republicans. Rep. Tony Tinderholt (R-HD94) attempted to restore the original intent of the bill, which would have allowed appointments regardless of party affiliation. Shockingly, only 28 Republicans voted for this. Charlie Geren was among the NO votes. (See the journal and search for "1399.")