what does "put anything in the field to match it"mean?
There might be worse to come. To the Presidential staff—Kennedy's lieutenants, aides, and agents were unanimous in this— it appeared highly probable that a superior force was on the way to intercept them. If they loitered in Dallas, they couldn't put anything in the field to match it. Their only chance was to hurry. They had temporized too long as it was. Perhaps that had been Rose's purpose, some of them thought; perhaps he had been sent to delay them. They had to move quickly, and Father Cain was no help. As Catholics the Irishmen were grateful for his blessing, but his timing was most inopportune.