Grassley strikes me as a rino that will try and use his position to oppose President Trumps conservative judicial nominations.
Grassley did a good job of getting judges through in President Trumps first two years if that’s a sign as to how he’d be in trumps second term.
Then you haven’t paid attention. Graham brought back blue slips for district court nominees after Grassley ignored them. And Grassley wrestled primary jurisdiction over Russian collusion away from NeverTrumper Richard Burr at Senate Intelligence. Since Grassley left Judiciary, Burr has claimed jurisdiction and attacked the President.
There is a limit to how long a senator can hold a major committee chair, and Grassley is at the limit for Finance, but still has time left to chair Judiciary.