Excitement over O'Rourke's candidacy has been bubbling just below the surface for Democrats in Texas and Washington for a few months now, with optimism built, largely, on O'Rourke's fundraising ability and President Donald Trump's surprisingly unimpressive poll numbers in the Lone Star State

Still, that optimism has been guarded -- largely because Democrats have been promising since at least 2002 that this is the election where the changing face of Texas -- less white, more Hispanic -- gives them a real chance to win a statewide election.

That optimism may be less guarded in the wake of this massive fundraising haul by O'Rourke. But, raising oodles of money doesn't guarantee an O'Rourke win. (If money = victory, then Tony Sanchez would have been governor and Ron Kirk would be in the Senate. They aren't .)

While O'Rourke's cash haul doesn't prove he's a sure-fire winner, it does reveal a few things about the race. Here are five.

1. Democratic donors hate Cruz: Sure, O'Rourke is young, personable and handsome. And, yes, Texas is a big state with : Sure, O'Rourke is young, personable and handsome. And, yes, Texas is a big state with lots and lots of donor money in it . But, a good chunk of O'Rourke's cash is the result of donors -- inside and outside of Texas -- who simply want to make Cruz sweat. Other than the current occupant of the White House, there's no Republican who Democrats hate more than Cruz -- largely as a result of his near-miss 2016 presidential campaign. That Cruz hatred among Democratic givers doesn't take away anything from O'Rourke; he saw the opportunity to run and capitalize on that dislike before anyone else did.

2. O'Rourke has a much higher $$$ ceiling: The $6.7 million O'Rourke raised between January 1 and March 31 came from 141,000 donations. Some simple back of the envelope math means that the average contribution was around $50. (Obviously that's a broad estimate, not a hard-and-fast number.) What it means is that O'Rourke should be able to go back to lots and lots of his donors and ask for more. (The contribution limit for an individual is $2,700 for the primary and another $2,700 for the general election.) The more he looks like he can be truly competitive, the easier that ask becomes.

3. PAC money is overrated: When O'Rourke announced his candidacy, he pledged not to accept any donations from political action committees -- a move aimed at proving he wasn't part of the DC swamp. Most independent observers crushed him for that decision, insisting that the residual benefits he would get from being able to cast himself as un-owned by the permanent political class would be overshadowed by how much money he would be sacrificing. (Cruz has raised north of $580,000 from PACs.) Turns out that O'Rourke hasn't needed PAC cash at all.

4. O'Rourke isn't a creation of the national Democratic Party: Per point No. 1, there's a tendency to assume that for any Democrat to raise the amount of money O'Rourke has that it must be coming from wealthy liberals on the two coasts who have cash to burn and just want to make Cruz's life difficult. Not so, at least as of February 18, the last day for which we have detailed information on O'Rourke's cash flow. (O'Rourke announced his fundraising through March 31 via press release but the actual report, which gives us a more detailed sense of where the money came from -- and how much of it he has left -- has yet to show up at the Federal Election Commission.) As of that date, 49.99% of O'Rourke's donations came from inside of Texas with the remainder from outside the state. That's a healthy split that suggests O'Rourke is not simply a creation of national Democrats but has actual, on-the-ground support among Texans.

5. This is a real race: Make no mistake: Cruz is still the favorite here. Texas remains a Republican state and despite what is expected to be a very good year for Democrats nationally, any credible GOPer starts with an edge over a Democrat in this state. That said, O'Rourke's fundraising will allow him to build a real voter identification and turnout effort statewide as well as battle Cruz on the TV airwaves. That doesn't guarantee victory. But it almost always ensures competitiveness.