Just a couple of weeks ago, the House of Representatives voted 420 to 0 to demand that the Mueller Report be made public. Every Republican voting supported the idea, and none voted against it.
Why did they vote that way? Because they, like most other Americans, expected the Mueller Report to present mainly a negative portrait of Donald Trump. They thought that by making the report public they could cherry-pick some parts of it that might not be so bad for Trump -- and by trumpeting those parts loudly, they could obfuscate and confuse. It was their faint hope of covering for Trump.
But then came Attorney General Barr's four-page whitewash of the Mueller Report. This week, the House Intelligence Committee voted to demand the full Mueller Report from Barr. Barr wants to give that committee a heavily-redacted version, but the committee is against that. They want the whole thing.
How did the Republicans on the committee vote? Every one of them voted against receiving the full un-redacted report. They no longer want the report to be public, but only the whitewashed version by Barr to be seen.
Why did they change their opinion? Because they liked Barr's four-page whitewash. Now they are afraid that the report contains material that would be damaging to Trump, and they don't want that information to reach the public (or change enough congressional minds to make impeachment possible).
That shows an incredible degree of hypocrisy. When they thought they could use the full report to help Trump, they supported its release. Now that they think the full report would hurt Trump, they oppose its release. They have no interest in helping the American people to learn the truth.