2016 hopefuls take to Twitter during 2015 State of the Union

As President Obama delivered his sixth annual State of the Union address Tuesday night, the field of potential 2016 candidates hoping to replace him weighed in online.

Sen. Rand Paul was out on Twitter early and often, and he wasn't afraid to use memes to criticize the president's proposals. When President Obama said he wanted two years of college to become "as free and universal in America as high school is today," Paul responded:

Even before the speech, Republican hopefuls like Louisiana Gov. Bobby Jindal tweeted their own previews:

And it wasn't just Republican potential candidates weighing in. Hillary Clinton, who leads the field of potential Democratic hopefuls, tweeted:

Former Virginia Sen. Jim Webb, a regular Democratic contrarian with a 2016 exploratory committee, live-tweeted the address. His hashtag? #webb2016.

Another potential Democratic hopeful, Massachusetts Sen. Elizabeth Warren, also chimed in, but with a decidedly less feisty tone than Webb.

Mitt Romney, who recently signaled interest in a possible third run for president, tweeted out his review of the address with a link to a longer statement on Facebook, calling it "a missed opportunity to lead."

And former Pennsylvania Sen. Rick Santorum, who is also considering another run, criticized the address with the help of his daughter Sarah, retweeting jabs she took at the president including one that referenced the Pittsburgh Penguins game also airing Tuesday night.