Wiktionary
vb. (present participle of run up against English)
Usage examples of "running up against".
One of Kahn's speculations had been that the natural form of human government was empire, and the natural tendency of an empire was to expand, there being no natural limit to that expansion save running up against another empire of equal or greater strength.
The American had announced his immediate departure, there would be no fear of running up against him.
The Race was running up against a deadline, not a situation familiar to its males and females.
It could be because there's so much tension about the embassy attacks, but he said he was running up against a blank wall.
And of course, working in the Ginger Cat, she was always running up against menespecially in the summer holidays.
I had no idea what we were running up against, but a dog which had been chained in the rear broke away from his fastening at sight of us, and ran at us with a lusty and savage growl.