Do I capitalize the C in Constitutional in this sentence?

The ‘C’ in ‘constitutional’ should be in lowercase in both of your examples. Unless the word is part of a proper name, or the first word in a sentence, it should not not be capitalized.

The adjective use isn’t capitalized here,
or at http://www.merriam-webster.com/dictionary/constitutional

Thanks.

@Pied_Pfeffer If Constitutional is part of a two-word proper noun such as “Constitutional Law” or “Constitutional Amendment X” then Constitutional should be capitalized, right?

No. constitutional law is not a proper noun and it should not be capitalised.

Constitutional Amendment X is the name of the amendent, and would be capitalized. Likewise, Constitutional Law as the title of a course or book would be capitalized. However, Justice Brandeis’ establishment of the implied right to privacy impacted constitutional law in the 20th century. would not be capitalize.

When you speak of the Constitution, it should be capitalized, otherwise, as in your examples, it should be lower cased.