Now you can tweet cash to candidates

If you ever wanted to tweet a few bucks to your favorite presidential candidate, your day has finally arrived.

Twitter and the mobile payment platform Square have teamed up to build a new interface that will allow users to make campaign donations to candidates without having to leave their Twitter feed.

The ability to make donations in tweets "is something campaigns have been asking for for a long time," said Jenna Golden, Twitter's head of political advertising sales. The system Twitter and Square are rolling out Tuesday will allow a campaign to tweet a "donate now" link that takes a user to a donation form without leaving their Twitter app. The user signs in and makes a donation and then can tweet that fact to their own followers. The next time the user wants to donate from a  tweet, all they have to do is enter the amount -- the system will remember them.

"We want people to have the opportunity to utilize this in the midst of key moments," Golden said, and Wednesday's debate should offer a good opportunity. Instead of simply tweeting about sharp exchange during the debate,  the candidate can also can tweet a donation appeal to supporters.

Golden said 12 presidential candidates are participating in the new system as it rolls out Tuesday.

Matt Compton, digital director at the Democratic National Committee says people are already coming to Facebook and Twitter to engage in political conversation and "when there is a national debate or a local event, they are participating in that event with their screen right there with them." The trick to reaching them there, he said, is that "if you are taking them off the platform, you see your engagement rates really fall off."

Compton said he is excited to test the new donation system because it has the "potential to introduce a higher level of engagement with supporters" on a platform they are already using, and "make it easier for people who want to engage to take action."

Twitter is not charging candidates to participate, though campaigns would presumably pay to target and promote the donation tweets.