Or, more solar and wind plugged into decentralised local grids. See: Germany and Denmark who are doing just that without the benefit of Texas Sun.
Lets check on Germany and run the numbers.
Germany peaked at 23.9 GW. At the peak, it was providing for 40% of Germany's electrical usage. Impressive.
But that's the peak. How about overall?
Wolfram Alpha gives 549.1 billion kwh/year for German's total electricity consumption. It also gives 19.1 billion kwh a year from solar, tide or waves and 46 billion kwh a year from wind.
Now we're mixing data from different years (so this is a rough estimate), but I'm seeing a total of 65.1 billion kwh/year from solar + wind, with a usage of 549.1 billion kwh/year. So about 12%. Compare this to to the 94.1 billion kwh/year from nuclear.
Now this neglects another problem - the variability of solar and wind. If solar and wind make up a small fraction of the grid, or it's possible to sell to neighboring countries, it's pretty easy to sell excess energy when it's windy/sunny, and use other power plants when it's not. I'm not sure what overcapacity the US would need if it primarily resorted to wind & solar power.
Not to mention the false dichotomy. We can build solar, we can build wind, we can build nuclear - but we can also build coal power plants, natural gas power plants, and oil power plants.
There's nothing preventing us from building both nuclear and renewable energy power plants in order to reduce the reliance on fossil fuel power plants. If you believe that anthropological global warming is a real problem, I'd suggest that reducing CO2 emissions through a combination of solar, wind & nuclear would be quicker than reducing CO2 emissions by just wind & solar, or by just nuclear.