WASHINGTON — A series of Gallup polls finds no sign yet that the Republican National Convention provided a bounce in support for presidential nominee Mitt Romney.

The contest between President Obama and Romney remained stuck in the days following the convention, according to Gallup daily tracking polls running through Saturday.

Party nominees usually receive a bounce in support after national political conventions and the extended case for their campaigns made in the televised proceedings.

Romney’s speech at his party’s convention also received low marks from the public. Only 38 percent rated his speech good or excellent, the lowest favorable response to any of the eight acceptance speeches that Gallup has tested since Republican Bob Dole was nominated in 1996, according to a poll that the research group released Monday.

Fewer Americans than in previous years said the convention overall made them more likely to support Republican. The convention had a “net impact” of 2 percentage points, which Gallup calculates by subtracting those who say the proceedings made them more likely to vote for the party nominee versus those who said it made them less likely to do so.

The “net impact” for the Republican convention, held last week in Tampa, Fla., was the lowest for any convention of either party on a question Gallup has asked since 1988.

The combined poll results back “the tentative conclusion that the Republican convention did not change the race,” Frank Newport, Gallup’s editor-in-chief, wrote in a blog post.

Gallup’s Sept. 1 daily tracking poll shows the presidential race unchanged at 48 percent for Obama to 47 percent for Romney, the same since Aug. 28.