If the president chose to appoint a federal judge that the Congress found unsuitable, which would have the final word?

Federal judges, including Supreme Court Justices, are appointed (nominated?) by the President, but must be approved by the US Senate. Here's an example:

http://en.wikipedia.org/wiki/John_E._Jones_III

Whose responsibility is it to determine if governmental acts are constitutional?

In the case where the President appoints a federal judge that the Congress finds unsuitable, the final word would ultimately rest with the Senate. The President has the power to nominate individuals for federal judgeships, but the Senate must confirm these nominations. This process is known as "advice and consent."

To understand this further, let's break down the constitutional process:

1. Presidential Nomination: The President nominates a candidate for a federal judgeship. This entails the President selecting an individual they believe is well-suited for the position.

2. Senate Judiciary Committee Evaluation: Once the President makes a nomination, the Senate Judiciary Committee conducts an evaluation. They review the nominee's qualifications, background, and any potential ethical concerns. The committee may request additional information, hold hearings, and interview the candidate.

3. Senate Confirmation Vote: After the Judiciary Committee's evaluation, they submit a report to the full Senate. The Senate then considers the nomination and holds a confirmation vote. A simple majority is generally required for confirmation, meaning that at least 51 Senators need to vote in favor of the nominee.

4. Potential Rejection: If the Senate finds the nominee unsuitable, they can choose to reject the nomination by not reaching the required majority vote. In this case, the President would need to nominate a different candidate for the position.

It's worth noting that the Senate's role in the judicial appointment process ensures a system of checks and balances, allowing for a collaborative decision between the executive (President) and legislative (Congress) branches of government. This mechanism prevents any individual or branch from having unilateral control over the appointment of federal judges.