Working under the presumption that no one is above the law...

[kentuck]

If Bob Mueller were to subpoena both Donald Trump and Don Jr before a Grand Jury, could Donald still give Don Jr a pardon?

I'm sure Mr Mueller has a strategy about how to handle a subject or target that refuses to cooperate? The trump has been playing games about giving an interview for over a year now. Perhaps it is time for Mueller to lay a subpoena on him? Let him take it to the Supreme Court. We are fairly certain that the Court will rule that no one is above the law, which is not what they would be saying, if they said that a President did not have to obey subpoenas or indictments. Dare him to take it to the Supreme Court!

Either we are a country of laws or we are a country of men.

At least, we will know where we stand.

[Lee-Lee]

1. The President can pardon anyone for any Federal crimes

He an do it even if they haven’t been charged, even if they don’t even know about the crimes yet, even if he doesn’t know the person name but just lists a blanket eligibility class people can fall into.

[kentuck]

2. Even if they are both charged for the same crime?

for example, the Trump Tower meeting and its cover-up?

[Lee-Lee]

3. Yup. Only in cases of impeachment is it limited

He can’t pardon someone convicted in an impeachment.

Aside from that it’s one of the least limited executive powers.

[3Hotdogs]

4. First of all, neither Qusay, Uday nor the Orange Skidmark can be forced to cooperate.

The 5th. Amendment prevents forcing "cooperative" testimony. They can be forced to appear before a Congressional committee or an investigative body. Once there however, they don't have to say a word, except for their name.

And yes, he can pardon his stupid sons for anything, known or unknown. We owe Gerald Ford for that and Congress for not challenging that by not immediately proposing an amendment to prevent it happening again.