Just use Google to check your state's rules on this.
Here's what Minnesota says. I've checked a few other states and they say essentially the same thing. Of course we should all be courteous and drive defensively, but in MN and many other states the law is clear on who has the right of way when merging, regardless of how big you think you are. Should people move over if they can? Of course. Should you push them over because of your size? Really?
Entering the Freeway
Entry ramps are short, one-way roads that provide access to freeways. At the end of most entry ramps, you will find an acceleration lane that allows you to increase your speed in order to safely merge with traffic that is already on the freeway.
To avoid disrupting traffic flow or “cutting off” other drivers when you merge, try to adjust your speed to accommodate vehicles already on the freeway. You must yield to other vehicles when you are merging.
Use your turn signal to let other drivers know your intention. Watch for an opening in the nearest traffic lane and merge into the flow of traffic when you are able to do so.
Do not stop on the ramp or in the acceleration lane unless it is absolutely necessary.
When an acceleration lane is not available, and a “Yield” sign is posted on the entry ramp, obey the sign. Stop, if it is necessary. Do not force your way into the lane of traffic