WASHINGTON - Campaigning in the GOP primaries earlier this year, Donald Trump liked to brag that he was the only Republican with broad enough appeal to put states in play that had not been competitive in ages.

He pointed to his native New York and to California, coastal states that typically go Democrat. He did not mention deep-red Texas, which last went for a Democrat in 1976.

But as Trump's campaign stumbles in the polls, Democratic nominee Hillary Clinton is expanding her efforts in a slew of traditionally Republican states, including Texas, where she is only six points down in the polls.

Citing last month's landmark endorsement by the Dallas Morning News, which had not backed a Democratic presidential candidate since World War II, the Clinton campaign is making a one-week ad buy in Houston, San Antonio, Austin and Dallas, touting the newspaper editorial.

Though Clinton still is a long shot in Texas, political analysts see it as a sign of her recent strength nationally and in the critical battleground states of Pennsylvania and Florida.

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"I don't think it's knowable at this point what a Texas ad buy would accomplish," veteran Texas Democratic operative Harold Cook said. "But I will say this: If the Democrat is buying ad time in Texas in a presidential election, it ain't a good year for the Republican."

The ad buy - estimated at about $1.5 million - is a modest investment for a state the size of Texas, but Democratic allies say it could represent a shift to a "50-state" strategy designed to expand on the 270 electoral votes needed to get to the White House.

As Trump faces a multitude of allegations focused on his behavior toward women, Clinton's new push into Texas and other Republican states also is seen as a chance to use her momentum to help Democrats in competitive House, Senate and other down-ballot races.

"Donald Trump is becoming more unhinged by the day, and that is increasing prospects for Democrats further down the ballot, because of higher-than-expected turnout and enthusiasm," Clinton campaign manager Robby Mook said Monday in a conference call with reporters.

Money to burn?

Mook also announced that the campaign would be adding $2 million in new spending on ads and direct mail in Arizona. Campaign aides said another $1 million is being deployed in Missouri and Indiana, the home of Gov. Mike Pence, Trump's running mate.

Texas Republican Party Chairman Tom Mechler declined to comment on the Clinton ad buy. A state GOP aide, however, questioned the impact of television ads running for a limited time in largely Democratic urban markets. While the ads may demonstrate some muscle-flexing on the part of the Clinton campaign, Republicans consider them a play for the more pervasive "earned media" of news and social media reaction.

Craig Goodman, a political scientist at the University of Houston in Victoria, said the Democrats are "playing with house money right now," citing reports that the Clinton campaign is flush with cash compared to Trump, who has taken in less than half of the $373 million reported so far by the Democrat. "They've got excess resources."

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The new ad comes as first lady Michelle Obama and Chelsea Clinton will campaign in Arizona. Vice-presidential nominee Tim Kaine spent time last week in Utah, where Trump faces a tough third-party challenge and Clinton received the endorsement of the Salt Lake Tribune. In Georgia, civil rights activist Jesse Jackson recently campaigned for Clinton.

Some campaign analysts estimate that a serious effort to compete in an expensive media state like Texas would require a push of more than $2 million a week from now until the Nov. 8 election. So far, the Clinton campaign has given no sign that it is ready to make an investment of that size, notwithstanding the six offices that Clinton and the Democratic National Committee have opened in the state.

Aimed at early voting

Texas Democrats see it as a hopeful sign that the national party is prepared to help make gains in the state Legislature, with at least eight competitive seats in the markets covered by the ads. Democrats, working on a big turnout effort, also are hoping to pick up a congressional seat in a Texas border district that includes parts of San Antonio, one of the markets where the Clinton ad will appear.

"In 2016, Texas Democrats have been laser-focused on building the permanent infrastructure necessary to make a stronger Texas," Texas Democratic Party Deputy Executive Director Manny Garcia said in a statement. "We're proud to have Secretary Clinton's campaign investing in that long-term vision. Every bit of support by national Democrats to help us make our case to Texas families helps get out the vote."

The Clinton ad appears to be timed for the beginning of early voting in Texas next Monday. It also comes on the heels of a very tumultuous two weeks for Trump, who has been battling accusations of sexually inappropriate behavior going back decades.

While many analysts see the Texas ad buy as a sign of a widening playing field, an aide to the Clinton camp emphasized that it highlights Clinton's "unique" endorsement by the Dallas Morning News.

The ad highlights the newspaper's opinion that Trump "plays on fear" and shows "a dangerous lack of judgment."

Trump currently leads in the state by nearly six percentage points, according to a RealClearPolitics average. While significant, it is a much smaller advantage than Republicans candidates generally have enjoyed in recent presidential elections. President Barack Obama lost the state by 16 points in 2012.

While the new ad is unlikely to reverse Clinton's fortunes in the state, it could present a challenge to Trump strategists deciding how to allocate their resources in the waning weeks of the campaign.

"It's an interesting little chess play," Cook said.