Longshot 2020 Democratic hopeful Mike Gravel tweeted on Friday his presidential campaign is "nearing its conclusion" and asked his followers where he should donate his campaign money. Gravel's campaign aired its first national ad on MSNBC at the end of June, and he told CBS News earlier that month that he had 45,000 donors.

Gravel followed up with a tweet saying they were still trying to qualify for the upcoming debates, but "we've always planned to have it end sometime in the next month or so."

Gravel failed to qualify for the first Democratic debate in June and is unlikely to qualify for the next debate in July. To qualify for those debates, candidates must have either 65,000 unique donors to their campaigns, with at least 200 donors in 20 different states, or obtain at least 1 percent in three polls recognized as legitimate by the committee. The Democratic National Committee capped the number of participants at 20.

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The DNC increased the qualification for the September debate, which is expected dramatically winnow down the number of participants. Candidates must have 130,000 unique donors in at least 20 states and will need to score at least 2 percent in at least four national or statewide polls in Iowa, New Hampshire and South Carolina.

Gravel asked if he should donate to Flint, RAICES (which provides legal aid for immigrants) or a Yemen-related charity.

Gravel, an 89-year-old former senator from Alaska whose campaign has focused on being anti-war, told CBSN in June that he delegates most of the day-to-day operations of his campaign to a pair of 18-year-olds.

"When I finally succumbed to their pressures, I gave them access to the Twitter and they gave me a veto power, which I've only exercised once, by warning them about rough language," he told CBSN's "Red & Blue." "Other than that, it's been their show."

Gravel has gained a Twitter presence by criticizing the other candidates.

There are 24 other Democrats seeking the party's nomination, and in a Quinnipiac poll released earlier this week, Gravel had less than 1% support.

Gravel previously ran for president in 2008.