Arriving @ Reagan on July 4.
Staying @ Embassy Suites-Convention Center

Will it be difficult to take the Metro lugging checked bags?
Blue line to Metro Center?

What time?

How many bags and how large? Can you manage on escalator?

Arriving 3 PM on 4th of July, so not a typical commuter day

Will have a carry-on apiece + 2 larger bags. 4 travelers.
Should be able to handle an escalator

If you can manage your own luggage, you shouldn't have a problem as there are escalators and elevators in the metro system. Just be sure you know which exit to take once you reach your destination and be prepared for a walk of a few blocks after you exit Metro Center. And yes, take the blue line to Metro Center. (There are directions on the Embassy Suites site, and you can also plan a route using the trip-planner feature of wmata.)

Hope that helps!

You can also take a Yellow line train from Reagan and get off at either Gallery Place or Mt Vernon Square/Convention Center. The distance from either of those stations to your hotel is a ten minute walk (vs. 7 minutes from Metro Center).

As you've already noted, the issue on the 4th will be the potential crowds on Metro headed into town for the Independence Day celebrations. It should be active but not unmanageable at that time in the afternoon.

It's going to be crazy on the Metro but even worse by taxi because of crowds. So I don't think you have a choice. But you may try to pare down your luggage. That always makes sense.

I don't think the metro will be that bad in the afternoon and especially going from National to Metro Center. The metro is mainly a nightmare after the fireworks, and for stations on the Mall and Union Station. I did it once and never again, but don't remember any big issues with the metro going down in later afternoon and I was going to the Mall.

I get the idea these "carryon" bags are full-size suitcases, at least 22 inches? Because if smaller than that, I don't see any big issue. I would never take the metro with some humongous suitcase that was 30 inches or anything, anyway. I don't see how one person could tote both a suitcase of 22 inches plus a larger one, though. If a small totebag and then a 22 incher, sure, I've done that.