Idiom: To run for
Hillary: Bill, I think I’m going to run for President in the next election.
Bill: That would be great. I’m sure you will do a great job.
Maria: Many people suggested I didn't run for it this time around, but I still think I can make a difference.
Neil: Go for it. I will support you all the way.
Meaning: The expression "to run for" means to try or attempt something.
In the example above, Hillary wants "to run for" president because she feels that she is capable of being a good president.
Aaron: Dude, my date wants to marry me after only one date.
John: It’s a good idea to run for it.
Aaron: It’s a bit scary considering we just met.
John: Uh, yeah. The situation sounds a little intense.
Meaning: In this example, the expression "to run for" means to run away or get away (as far as possible) from someone/something.
In the example above, John suggests "to run for it” because he feels that the person Aaron is dating may be pushing the relationship faster than normal.